MRI-guided medical interventional systems and methods

ABSTRACT

An MRI-guided interventional system includes a trajectory guide frame for guiding an interventional device with respect to a patient in an MRI-guided procedure and including a base, a platform, a targeting cannula, and a stabilizer mechanism. The platform is mounted on the base and includes a support table and a moving plate that is translatable relative to the support table and the base along a translational axis. The targeting cannula is mounted on the moving plate for movement therewith and includes an elongate guide bore defining a trajectory axis. The stabilizer mechanism is operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base. The frame is operable to translate the moving plate along the translational axis relative to the base to position the trajectory axis. The translational axis is transverse to the trajectory axis.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/236,950, filed Sep. 24, 2008, now U.S. PatentNo. 8,374,677, issued Feb. 12, 2013, which is a continuation-in-partapplication of U.S. patent application Ser. No. 12/134,412, filed Jun.6, 2008, now U.S. Patent No. 8,175,677, issued May 8, 2012, which claimsthe benefit of and priority to U.S. Provisional Patent Application No.60/933,641, filed Jun. 7, 2007, and to U.S. Provisional PatentApplication No. 60/974,821, filed Sep. 24, 2007, the disclosures ofwhich are incorporated herein by reference as if set forth in theirentireties.

FIELD OF THE INVENTION

The present invention relates generally to medical systems and methodsand, more particularly, to in vivo medical systems and methods.

BACKGROUND OF THE INVENTION

Deep Brain Stimulation (DBS) is becoming an acceptable therapeuticmodality in neurosurgical treatment of patients suffering from chronicpain, Parkinson's disease or seizure, and other medical conditions.Other electro-stimulation therapies have also been carried out orproposed using internal stimulation of the sympathetic nerve chainand/or spinal cord, etc.

One example of a prior art DBS system is the Activa® system fromMedtronic. Inc. The Activa® system includes an implantable pulsegenerator stimulator that is positioned in the chest cavity of thepatient and a lead with axially spaced apart electrodes that isimplanted with the electrodes disposed in neural tissue. The lead istunneled subsurface from the brain to the chest cavity connecting theelectrodes with the pulse generator. These leads can have multipleexposed electrodes at the distal end that are connected to conductorswhich run along the length of the lead and connect to the pulsegenerator placed in the chest cavity.

It is believed that the clinical outcome of certain medical procedures,particularly those using DBS, may depend on the precise location of theelectrodes that are in contact with the tissue of interest. For example,to treat Parkinson's tremor, presently the DBS probes are placed inneural tissue with the electrodes transmitting a signal to the thalamusregion of the brain. DBS stimulation leads are conventionally implantedduring a stereotactic surgery, based on pre-operative MRI and CT images.These procedures can be long in duration and may have reduced efficacyas it has been reported that, in about 30% of the patients implantedwith these devices, the clinical efficacy of the device/procedure isless than optimum. Notwithstanding the above, there remains a need foralternative MRI-guided interventional tools for DBS, as well as forother interventional medical procedures.

SUMMARY OF THE INVENTION

In view of the above, MRI-guided interventional systems and methods areprovided. Embodiments of the present invention provide methods, devicesand systems for highly localized placement and/or delivery of diagnosticor therapeutic devices or substances.

According to embodiments of the present invention, an MRI-guidedinterventional system includes a frame with a cooperating targetingcannula. The frame is configured to be secured to the body of a patient,and is configured to translate and rotate such that the targetingcannula can be positioned to a desired intrabody trajectory. The framemay include one or more MRI-visible fiducial markers that allow framelocation/orientation to be determined within an MRI image.

Embodiments of the present invention may be particularly suitable forplacing neuro-modulation leads, such as Deep Brain Stimulation (“DBS”)leads, implantable parasympathetic or sympathetic nerve chain leadsand/or CNS stimulation leads, as well as other devices within the brain.

Embodiments of the present invention may be suitable for a number ofinterventional procedures in many locations inside the body including,but not limited to, brain, cardiac, spinal, urethral, and the like.Embodiments of the present invention may be suitable for a number ofMRI-guided drug delivery procedures, MRI-guided ablation procedures,etc.

A plurality of user-activatable actuators are operably connected to theframe and are configured to translate and rotate the frame relative tothe body of a patient so as to position the targeting cannula to adesired intrabody trajectory. In some embodiments, the actuators aredials or thumbscrew-type devices that allow manual manipulation thereof.In other embodiments, the actuators are manipulated remotely usingremote controls and cables.

The targeting cannula includes an axially-extending guide boretherethrough that is configured to guide placement of an interventionaldevice in vivo. Various instrumentation and equipment (e.g., stimulationleads, ablation probes or catheters, injection or fluid deliverydevices, biopsy needles, extraction tools, etc.) can be inserted throughthe targeting cannula to execute diagnostic and/or surgical procedures.

According to some embodiments of the present invention, the frameincludes a base, a yoke movably mounted to the base and that isrotatable about a roll axis, and a platform movably mounted to the yokeand that is rotatable about a pitch axis. The platform includes an X-Ysupport table that is configured to move in an X-direction andY-direction relative to the platform. The base has a patient accessaperture formed therein, and is configured to be secured to the body ofa patient such that the aperture overlies an opening in the body. A rollactuator is operably connected to the yoke and is configured to rotatethe yoke about the roll axis. A pitch actuator is operably connected tothe platform and is configured to rotate the platform about the pitchaxis. An X-direction actuator is operably connected to the platform andis configured to move the X-Y support table in the X-direction, AY-direction actuator is operably connected to the platform and isconfigured to move the X-Y support table in the Y-direction.

The base may include a plurality of locations for attachment to a bodyof a patient via fasteners. In some embodiments, one or more attachmentlocations may include multiple adjacent apertures configured to receivea fastener therethrough. For embodiments where the frame is configuredto be attached to the skull of a patient, the base can be configured tobe secured to the skull of a patient such that the patient accessaperture overlies a burr hole formed in the patient skull.

According to some embodiments of the present invention, the yokeincludes a pair of spaced apart arcuate arms. The platform engages andmoves along the yoke arcuate arms when rotated about the pitch axis. Thebase includes at least one arcuate arm. The yoke engages and moves alongthe base arcuate arm when rotated about the roll axis.

According to some embodiments of the present invention, at least one ofthe yoke arcuate arms includes a thread pattern formed in a surfacethereof. The pitch actuator includes a rotatable worm with teethconfigured to engage the thread pattern. Rotation of the worm causes theplatform to rotate about the pitch axis. Similarly, at least one of thebase arcuate arms includes a thread pattern formed in a surface thereof.The roll actuator includes a rotatable worm with teeth configured toengage the thread pattern, and wherein rotation of the worm causes theyoke to rotate about the roll axis.

In some embodiments, the actuators are color-coded such that eachdifferent actuator has a respective different color. This allows a userto quickly determine which actuator is the correct one for a particulardesired movement of the frame.

According to some embodiments of the present invention, an ergonomicremote control unit is provided that allows a user to remotely translateand rotate the frame such that the targeting cannula can be positionedto a desired intrabody trajectory. The remote control unit includes aplurality of position controls. Each control is operably connected to arespective frame actuator by a respective cable. One or more of theposition controls can include both “gross” and “fine” adjustments.

Movement of a position control operates a respective actuator via arespective control cable. For example, the remote control unit includesa roll adjustment control, a pitch adjustment control, an X-directionadjustment control, and a Y-direction adjustment control. A roll controlcable is operably connected to the roll adjustment control and to theroll actuator. Movement of the roll adjustment control operates the rollactuator via the roll control cable. A pitch control cable is operablyconnected to the pitch adjustment control and to the pitch actuator.Movement of the pitch adjustment control operates the pitch actuator viathe pitch control cable. An X-direction control cable is operablyconnected to the X-direction control and to the X-direction actuator.Movement of the X-direction adjustment control operates the X-directionactuator via the X-direction control cable. A Y-direction control cableis operably connected to the Y-direction control and to the Y-directionactuator. Movement of the Y-direction adjustment control operates theY-direction actuator via the Y-direction control cable.

In some embodiments, the roll adjustment control, pitch adjustmentcontrol, X-direction adjustment control, and Y-direction adjustmentcontrol are manually-operated thumbwheels, and rotation of eachthumbwheel by a user causes corresponding axial rotation of a respectivecontrol cable and corresponding axial rotation of a respective actuator.In other embodiments, one or more of the roll adjustment control, pitchadjustment control, X-direction adjustment control, and Y-directionadjustment control are electric motor-assisted, rotatable controls.

In some embodiments, locking mechanisms are associated with the remoteunit position controls, and are configured to prevent user operation ofthe controls when in a locked position.

In some embodiments, each control cable has a geometrically shaped rigidend that is configured to removably engage a free end of a respectiveactuator. Each control cable rigid end may have a shape that isdifferent from the other control cable rigid ends such that each controlcable free end can only removably engage one of the respective actuatorfree ends. Each control cable includes a flexible elastomeric collarthat is configured to surround a respective actuator free end and tomaintain engagement of a cable end to a respective actuator free end.Each flexible collar can be rolled or folded back then released to coverand conformably compress against an actuator free end to hold the end ofthe cable in position; then the collar can be pushed back to easilyrelease the cable from an actuator free end.

According to some embodiments, a safety lanyard may be used to connectthe remote control module to a rigid object, such as a patient supportframe or head coil (or even the gantry or gantry housing) to preventover extension of the cables or unwanted adjustments to the trajectory.

According to some embodiments, a drape is provided that is configured tobe positioned near the body of a patient within a magnet of an MRIscanner. The drape includes a pocket that is configured to removablyreceive the remote control unit therein. The drape also includes one ormore apertures through which the cables extend from the remote controlunit to the frame.

According to some embodiments of the present invention, a camera and/orvideo imaging device is removably secured to the frame via a bracket.The bracket includes a sleeve that is configured to slidably receive theimaging device therein.

An elongated tubular member extends through the platform and yoke and issecured to the X-Y table of the frame. The targeting cannula is slidablysecured within the tubular member and is movable between extended andretracted positions. The targeting cannula is configured to translate inresponse to translational movement of the X-Y support table and torotate in response to rotational movement of the yoke and platform todefine different axial trajectories extending through the patient accessaperture of the base. The tubular member is configured to lock thetargeting cannula in an extended position and in a retracted position.

A depth stop is removably secured within a proximal end of the tubularmember. The depth stop receives a sheath therein, and is configured tolimit the distance that the sheath can extend into the body of apatient. The sheath is configured to receive an elongated interventionaldevice (e.g., imaging probe, stimulation lead, ablation device,injection device, etc.). In some embodiments, the sheath is removable. Alocking mechanism is removably secured to the depth stop and isconfigured to prevent axial movement of an elongated interventionaldevice extending through the sheath.

According to some embodiments of the present invention, an MRI-guidedinterventional system includes a frame with a cooperating targetingcannula that has a guide bore therethrough that is configured to guideplacement of an interventional device in vivo. The frame is configuredto rotate such that the targeting cannula can be positioned to a desiredintrabody trajectory. The frame includes a base having a patient accessaperture formed therein, wherein the base is configured to be secured tothe body of a patient; a yoke movably mounted to the base and rotatableabout a roll axis; and a platform movably mounted to the yoke androtatable about a pitch axis. A plurality of user-activatable actuatorsare operably connected to the frame and are configured to rotate theframe relative to the body of the patient so as to position thetargeting cannula to a desired intrabody trajectory. In someembodiments, the actuators are color-coded such that each actuator has arespective different color. In some embodiments, the frame includes aroll actuator operably connected to the yoke and configured to rotatethe yoke about the roll axis; and a pitch actuator operably connected tothe platform and configured to rotate the platform about the pitch axis.

In some embodiments, the system includes a remote control unitcomprising a plurality of elongate control devices. Each control deviceincludes first and second elongate rods axially connected at respectivefirst ends via a first cable. The first rod second end is operablyconnected to a respective actuator via a second cable. Rotationalmovement of the second end of the second rod operates the actuator viathe second cable. Each second cable may have a geometrically shapedrigid end configured to removably engage a free end of a respectiveactuator.

MRI-guided interventional methods, according to embodiments of thepresent invention, include affixing a frame with a cooperating targetingcannula to the body of a patient, wherein the frame is configured totranslate and rotate such that the targeting cannula can be positionedto a desired intrabody access path trajectory. The targeting cannulaincludes a guide bore therethrough that is configured to guide placementof an interventional device in vivo. The targeting cannula position isadjusted (e.g., rotated about a roll axis, rotated about a pitch axis,and/or translated in X-Y directions) so that the targeting cannula isaligned with the desired access path trajectory while the patient ispositioned within a magnetic field associated with an MRI scanner. Oncethe targeting cannula is repositioned, an interventional device isinserted through the targeting cannula guide bore and into the body ofthe patient for therapeutic and/or diagnostic purposes. The targetingcannula is movable between retracted and extended positions, and ismoved to the extended position and locked in the extended position priorto the adjusting the access path trajectory thereof.

The necessary rotational and translational adjustments required toreposition the targeting cannula to the desired access path trajectoryare displayed to a user via a graphical user interface. Both the actualaccess path trajectory and desired access path trajectory can bedisplayed, as well. In addition, the user can view the actual trajectorychanging as he/she adjusts the position of the targeting cannula. Insome embodiments, an indication of when the actual trajectory is alignedwith a desired trajectory can be displayed to the user.

According to some embodiments, an MRI-guided interventional system foruse with a body of patient and an interventional device includes a baseand a targeting cannula. The base is configured to be secured to thebody of the patient. The targeting cannula has an elongate guide boreextending axially therethrough and an inlet and an outlet at opposedends of the guide bore. The guide bore defines a trajectory axisextending through the inlet and the outlet and being configured to guideplacement of the interventional device. The frame is operable to movethe targeting cannula relative to the base to position the trajectoryaxis to a desired intrabody trajectory to guide placement of theinterventional device in vivo. The inlet tapers from an outer diameterdistal from the guide bore to an inner diameter proximate the guide boreto guide and facilitate insertion of the interventional device into theguide bore.

The system may include an elongate interventional device configured tobe serially inserted through the inlet, the guide bore and the outletand into the body of the patient in vivo.

In some embodiments, the trajectory guide frame further includes atubular cannula guide member defining a cannula guide member passage andhaving an inlet and outlet on opposed ends of the cannula guide memberpassage, and the targeting cannula is slidably mounted within thecannula guide member passage to move between extended and retractedpositions. In some embodiments, the targeting cannula has a main bodyportion and an extension portion, the extension portion including theinlet of the targeting cannula, and the main body portion has a primaryouter diameter that is greater than a diameter of the inlet of thecannula guide member and the extension portion has a reduced outerdiameter that is less than the primary outer diameter and is sized to bereceived in the inlet of cannula guide member when the targeting cannulais in the retracted position.

The inlet of the cannula guide member can have a diameter that is atleast as great as the outer diameter of the inlet of the targetingcannula.

According to embodiments of the present invention, an MRI-guidedinterventional system for use with a body of patient and aninterventional device includes a base, a targeting cannula, and abracket. The base is configured to be secured to the body of thepatient. The targeting cannula has an elongate guide bore extendingaxially therethrough, defining a trajectory axis, and being configuredto guide placement of the interventional device. The frame is operableto move the targeting cannula relative to the base to position thetrajectory axis to a desired intrabody trajectory to guide placement ofthe interventional device in vivo. The bracket is secured to thetrajectory guide frame such that the bracket is rotatable about thetrajectory axis and axially fixed with respect to the trajectory axis.The bracket is configured to receive a light transmission scope tosecure the light transmission scope to the trajectory guide frame.

In some embodiments, the trajectory guide frame includes one of a grooveand a projection and the bracket includes the other of the groove andthe projection, and the projection is cooperatively seated in the grooveto permit rotation of the bracket with respect to the trajectory axiswhile preventing axial translation of the bracket along the trajectoryaxis. The groove may be configured to limit rotation of the bracket withrespect to the trajectory axis to a prescribed range of rotation.

In some embodiments, the bracket and the trajectory guide frame areconfigured to permit the bracket to be alternatively mounted on each oftwo opposed sides of the targeting cannula.

The bracket may be configured to removably snap fit onto the trajectoryguide frame.

The system can include a locking device to secure the light transmissionscope to the bracket.

According to some embodiments, the system includes the lighttransmission scope and the light transmission scope is a fiber scope.

According to embodiments of the present invention, a trajectory guideframe for guiding an interventional device with respect to a body of apatient in an MRI-guided procedure includes a base, a yoke and atargeting cannula. The base has a patient access aperture therein. Thebase is configured to be secured to the body of the patient. The yoke ismountable on the base in a prescribe orientation with respect to thebase. The targeting cannula is mounted on the yoke for movementtherewith relative to the base. The targeting cannula includes a guidebore therethrough that is configured to guide placement of theinterventional device in vivo. First and second spaced apart pivot holesare provided in one of the base and the yoke and first and second pivotpins are associated with the other of the base and the yoke. The yoke isconfigured to be mounted on the base in the prescribed orientation withthe first pivot pin received in the first pivot hole and the secondpivot pin received in the second pivot hole, whereby the yoke ispivotable relative to the base about the first and second pivot pinsabout a roll axis. The first and second holes are relatively configuredto prevent operative engagement between the first pivot pin and thesecond pivot hole to inhibit pivotal mounting of the yoke on the base inan orientation other than the prescribed orientation.

The first pivot pin may have a greater diameter than the second pivotpin and the second pivot hole.

In some embodiments, at least one of the first and second pivot pins isadjustable to selectively change a length of said adjustable pivot pinextending toward its associated one of the first and second pivot holes.

In some embodiments, the first and second pivot holes are located in thebase, and the base includes a pair of spaced apart mount arms eachhaving a guide slot therein extending to a respective one of the firstand second guide holes to receive and guide the first and second pivotpins to the first and second pivot holes. According to some embodiments,the first and second pivot pins are located on first and second yokemount arms, respectively, and the base is configured to elasticallydeflect the first and second yoke mount arms apart as the first andsecond pivot pins are slid down the guide slots to the first and secondpivot holes to mount the yoke on the base.

The first and second pivot pins can be releasably spring loaded intoengagement with the first and second pivot holes to permit the yoke tobe selectively dismounted from the base.

According to embodiments of the present invention, a trajectory guideframe for guiding an interventional device with respect to a body of apatient in an MRI-guided procedure includes a base, a platform, atargeting cannula, and a stabilizer mechanism. The base has a patientaccess aperture therein. The base is configured to be secured to thebody of the patient. The platform is mounted on the base and includes asupport table and a moving plate that is movable relative to the supporttable and the base. The targeting cannula is mounted on the moving platefor movement therewith relative to the support table and the base. Thetargeting cannula includes a guide bore therethrough that is configuredto guide placement of the interventional device in vivo. The stabilizermechanism is operable to selectively control movement between thesupport table and the moving plate to stabilize a position of thetargeting cannula with respect to the base.

The trajectory guide frame may further include a yoke movably mounted onthe base and rotatable relative to the base about a pivot axis. Theplatform is mounted on the yoke for rotation therewith and the platformis configured to permit translational movement of the moving plate withrespect to the yoke.

In some embodiments, the stabilizer mechanism includes an adjustmentdevice and a rub bar, and the rub bar and the support tablecooperatively define a slot through which the moving plate slides incontact with the rub bar. The adjustment device may be operable to applya load to the rub bar to compressively load the moving plate in the slotbetween the support table and the rub bar. The loading device caninclude at least one screw.

According to embodiments of the present invention, a trajectory guideframe for guiding an interventional device with respect to a body of apatient in an MRI-guided procedure includes a base, a platform, atargeting cannula and a lock clip. The base has a patient accessaperture therein. The base is configured to be secured to the body ofthe patient. The platform is mounted on the base and includes a supporttable and a moving plate that is movable relative to the support tableand the base. The targeting cannula is mounted on the moving plate formovement therewith relative to the support table and the base. Thetargeting cannula includes a guide bore therethrough that is configuredto guide placement of the interventional device in vivo. The lock clipis mounted on the platform and configured, when in a locking position,to prevent relative movement between the support table and the movingplate. The lock clip is removable to permit relative movement betweenthe support table and the moving plate.

The trajectory guide frame may include a first lock hole in the supporttable and a second lock hole in the moving plate. The lock clip extendsthrough the first and second holes when in the locking position.

According to some embodiments, a trajectory guide frame for guiding aninterventional device with respect to a body of a patient in anMRI-guided procedure includes a base, a targeting cannula and anMRI-visible fiducial marker. The base has a patient access aperturetherein. The base is configured to be secured to the body of thepatient. The base defines a fiducial cavity and a tab aperturecommunicating with a fiducial cavity. The targeting cannula is mountedon the base for movement relative thereto. The targeting cannulaincludes a guide bore therethrough that is configured to guide placementof the interventional device in vivo. The MRI-visible fiducial marker ismounted on the base and includes a body portion containing anMRI-visible material and a fill tab extending from the body portion. Atleast a portion of the body portion is disposed in the fiducial cavityand the fill tab extends through the tab aperture.

According to some embodiments, a trajectory guide frame for guiding aninterventional device with respect to a body of a patient in anMRI-guided procedure includes a base, a targeting cannula and anMRI-visible fiducial marker. The base has a patient access aperturetherein. The base is configured to be secured to the body of a patient.The base includes a fiducial mount structure and a fiducial locatorfeature associated with the fiducial mount structure. The targetingcannula is mounted on the base for movement relative thereto. Thetargeting cannula includes a guide bore therethrough that is configuredto guide placement of the interventional device in vivo. The MRI-visiblefiducial marker is mounted on the fiducial mount structure. TheMRI-visible fiducial marker is toroidal and defines a central opening.The fiducial marker extends into the central opening to positivelylocate the MRI-visible fiducial marker with respect to the base.

According to some embodiments, a trajectory guide frame for guiding aninterventional device with respect to a body of a patient in anMRI-guided procedure includes a base, a targeting cannula and aplurality of MRI-visible fiducial markers. The base has a patient accessaperture therein. The base is configured to be secured to the body of apatient. The targeting cannula is mounted on the base for movementrelative thereto. The targeting cannula includes a guide boretherethrough that is configured to guide placement of the interventionaldevice in vivo. The plurality of MRI-visible fiducial markers aremounted on the base. The MRI-visible fiducial markers are relativelypositioned in an asymmetric layout to facilitate positive determinationof an orientation of the base in free space from an MR image.

In some embodiments, the plurality of MRI-visible fiducial markersincludes at least first, second and third MRI-visible fiducial markerseach located on a circle, and a circumferential spacing between thefirst and second MRI-visible fiducial markers is less than acircumferential spacing between the first and third MRI-visible fiducialmarkers.

Further features, advantages and details of the present invention willbe appreciated by those of ordinary skill in the art from a reading ofthe figures and the detailed description of the preferred embodimentsthat follow, such description being merely illustrative of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of an MRI-guided interventional system,according to some embodiments of the present invention.

FIG. 1B illustrates a user interface that displays, and that allows auser to adjust, the trajectory of a targeting cannula, according to someembodiments of the present invention.

FIG. 2A is a top perspective view of a burr hole formed in the skull ofa patient, and a burr hole ring overlying the burr hole and secured tothe skull.

FIG. 2B is a top perspective view of a removable centering devicepositioned on the burr hole ring of FIG. 1.

FIG. 3A is a perspective view of a trajectory frame utilized in theMRI-guided interventional system, according to some embodiments of thepresent invention.

FIGS. 3B-3E are side view, schematic illustrations of the trajectoryframe being secured to the skull of a patient.

FIGS. 4-5 are partial perspective views of the frame of FIG. 3Aillustrating the base of the frame being positioned on the skull of apatient with the centering device of FIG. 2B extending through thepatient access aperture.

FIG. 6 illustrates the base secured to the skull of a patient.

FIG. 7 is an enlarged partial perspective view of the base illustratingan attachment location with a pair of adjacent apertures for receivingfasteners therethrough, according to some embodiments of the presentinvention.

FIG. 8A is a perspective view of the frame of FIG. 3A secured to thebody (e.g., skull) of a patient, and with the targeting cannula in anextended position.

FIG. 8B is a cut-away perspective view of the frame of FIG. 3A,illustrating a targeting cannula according to some embodiments of thepresent invention.

FIGS. 9 and 10A-10C illustrate a remote control unit for remotelycontrolling the positioning actuators of the frame of FIG. 3A, accordingto some embodiments of the present invention.

FIG. 11 is a perspective view of the base of the frame of FIG. 3Aillustrating fiducial markers associated therewith and illustrating anarcuate arm with a thread pattern formed in a surface thereof that isconfigured to be engaged by a roll axis actuator, according to someembodiments of the present invention.

FIG. 12 is a partial perspective view of the frame of FIG. 3Aillustrating a yoke arcuate arm with a thread pattern formed in asurface thereof that is configured to be engaged by a pitch axisactuator, according to some embodiments of the present invention.

FIGS. 13A-13B illustrate an optic fiber scope for a video imaging cameramounted to the frame of FIG. 3A so as to view a burr hole, according tosome embodiments of the present invention.

FIG. 14 is an enlarged, partial perspective view of the frame of FIG. 3Aillustrating the targeting cannula locked in an extended position,according to some embodiments of the present invention.

FIG. 15 is an enlarged, partial perspective view of the frame of FIG. 3Aillustrating control cables removably engaged with respective actuators,and illustrating flexible elastomeric collars configured to surroundrespective actuator free ends and to maintain engagement of the cableends to a respective actuator free end, according to some embodiments ofthe present invention.

FIG. 16A is a partial perspective view of a frame of an MRI-guidedinterventional system, according to other embodiments of the presentinvention, and illustrating actuators positioned on a side of the frameand illustrating control cables removably engaged with the respectiveactuators.

FIG. 16B is a partial perspective view of an exemplary prototypeactuator illustrating a remote control cable end about to be insertedinto a slot in the actuator free end, according to some embodiments ofthe present invention.

FIG. 16C is a partial perspective view of the actuator of FIG. 16B withthe remote control cable end inserted into the actuator and with anelastomeric collar engaging the free end of the actuator to prevent thecable from being inadvertently removed from the actuator.

FIGS. 16D-16E are partial perspective views of the actuator of FIG. 16Cillustrating removal of the elastomeric collar and cable (FIG. 16E) fromthe free end of the actuator.

FIG. 17 illustrates the frame of FIG. 3A secured to the skull of apatient and illustrates a desired trajectory for an interventionaldevice, and also illustrates the actual trajectory of the interventionaldevice as oriented by the frame.

FIG. 18 illustrates the frame of FIG. 17 after reorientation viamanipulation of one or more frame actuators such that the actualtrajectory is adjusted to be in alignment with the desired trajectory.

FIG. 19A is an enlarged, partial perspective view of the frame of FIG.3A illustrating the X-Y support table, according to some embodiments ofthe present invention.

FIG. 19B schematically illustrates X-Y translation of an X-Y supporttable and rotational movement of the yoke and platform, according tosome embodiments of the present invention.

FIG. 19C is partial perspective view of an X-Y support table, accordingto some embodiments, with elements removed to reveal internal componentsof an X-direction actuator and Y-direction actuator.

FIG. 20 illustrates a depth stop with a peel-away sheath insertedtherein, according to some embodiments of the present invention.

FIG. 21 illustrates an imaging probe inserted within the peel-awaysheath of FIG. 20 and with the depth stop advanced to a depth mark onthe peel-away sheath, according to some embodiments of the presentinvention.

FIG. 22 illustrates the depth stop and probe being inserted into thetargeting cannula of the frame of FIG. 3A.

FIG. 23 illustrates the probe of FIG. 22 being removed from thepeel-away sheath and depth stop.

FIG. 24 illustrates a lead lock secured to the depth stop of FIG. 23.

FIG. 25 illustrates a lead being inserted through the lead lock of FIG.24 and through the targeting cannula.

FIG. 26A is a perspective view of the frame of FIG. 3A with the lead ofFIG. 25 inserted into the brain of a patient and with the peel-awaysheath being removed, according to some embodiments of the presentinvention.

FIG. 26B is an enlarged view of the distal end of the peel-away sheathwith the distal end of the lead extending therethrough, prior to removalof the sheath.

FIG. 27 illustrates a clamp inserted within and attached to the burrhole ring that is configured to prevent the lead from being retractedfrom the brain as the frame is removed from the skull of the patient.

FIGS. 28A-28G are side view, schematic illustrations of the trajectoryframe illustrating exemplary operation of the device for the insertionof interventional devices within the body of a patient via the targetingcannula.

FIG. 29 illustrates a drape configured to be positioned adjacent to apatient and that has a pocket configured to removably receive the remotecontrol unit of FIGS. 9 and 10A-10C.

FIG. 30 illustrates a safety lanyard according to some embodiments ofthe present invention, wherein the safety lanyard is attached to theremote control unit of FIGS. 9 and 10A-10C and to a rigid object toprevent inadvertent detachment of the control cables.

FIG. 31 is a schematic illustration of a patient positioned within anMRI scanner and a user utilizing a remote control apparatus 400 anddisplay monitors to position a targeting cannula, according to someembodiments of the present invention.

FIGS. 32A-32C illustrate a remote control unit for remotely controllingthe positioning actuators of the frame of FIG. 3A, according to otherembodiments of the present invention.

FIG. 33 is a perspective view of a trajectory guide frame and a camerabracket according to further embodiments of the present invention.

FIG. 34 is a top plan view of the trajectory guide frame of FIG. 33 witha yoke and platform thereof removed and the camera bracket shown mountedthereon in alternative positions.

FIG. 35 is a partial perspective view of the trajectory guide frame andcamera bracket of FIG. 33.

FIG. 36 is an exploded, partial perspective view of the trajectory guideframe and camera bracket of FIG. 33.

FIG. 37 is a cross-sectional view of the trajectory guide frame andcamera bracket of FIG. 33 taken along the line 37-37 of FIG. 35.

FIG. 38 is a cross-sectional view of the trajectory guide frame andcamera bracket of FIG. 33 taken along the line 38-38 of FIG. 33, whereina targeting cannula thereof is in a retracted position.

FIG. 39 is a partial top plan view of the trajectory guide frame of FIG.33.

FIG. 40 is a partial cross-sectional view of the trajectory guide frameof FIG. 33, wherein the targeting cannula is in an extended position.

FIG. 41 is a partial cross-sectional view of the trajectory guide frameof FIG. 33, wherein an alternative targeting cannula according tofurther embodiments of the present invention is in a retracted position.

FIGS. 42 and 43 are exploded perspective views of a base and a yoke ofthe trajectory guide frame of FIG. 33 illustrating a mounting systemaccording to some embodiments of the present invention.

FIG. 44 is a cross-sectional view of the base and yoke of FIG. 42 takenalong the line 44-44 of FIG. 43.

FIG. 45 is a partial perspective view of the trajectory guide frame ofFIG. 33 illustrating a stabilizer system according to some embodimentsof the present invention.

FIG. 46 is an exploded, partial perspective view of the trajectory guideframe of FIG. 33.

FIG. 47 is a further perspective view of the trajectory guide frame ofFIG. 33.

FIG. 48 is a perspective view of a lock clip for use with the trajectoryguide frame of FIG. 33.

FIG. 49A is a top plan view of the base of the trajectory guide frame ofFIG. 33 illustrating a layout of MRI-visible fiducial markers of thetrajectory guide frame.

FIG. 49B is a schematic view of a display including an image based onMRI image data including representations of a patient's head and a baseand fiducial markers of the trajectory guide frame.

FIG. 50 is an enlarged, fragmentary, perspective view of the trajectoryguide frame of FIG. 33 illustrating a fiducial marker positioningfeature according to some embodiments of the present invention.

FIG. 51 is an enlarged, fragmentary, perspective view of the trajectoryguide frame of FIG. 33 illustrating a fiducial marker tab relief featureaccording to some embodiments of the present invention.

FIG. 52 is a fragmentary, perspective view of an MRI-guidedinterventional system according to embodiments of the present inventionincluding a pair of the trajectory guide frames of FIG. 33 mounted on apatient's head to conduct a bilateral surgical procedure on the patient.

DETAILED DESCRIPTION

The present invention now is described more fully hereinafter withreference to the accompanying drawings, in which some embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, thethickness of certain lines, layers, components, elements or features maybe exaggerated for clarity.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising.” when used in this specification, specify thepresence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the specification andrelevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein. Well-known functions orconstructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being “on”,“attached” to, “connected” to, “coupled” with, “contacting”, etc.,another element, it can be directly on, attached to, connected to,coupled with or contacting the other element or intervening elements mayalso be present. In contrast, when an element is referred to as being,for example, “directly on”, “directly attached” to, “directly connected”to, “directly coupled” with or “directly contacting” another element,there are no intervening elements present. It will also be appreciatedby those of skill in the art that references to a structure or featurethat is disposed “adjacent” another feature may have portions thatoverlap or underlie the adjacent feature.

Spatially relative terms, such as “under”, “below”, “lower”, “over”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus, the exemplary term “under” can encompass both anorientation of “over” and “under”. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly”, “downwardly”, “vertical”, “horizontal” and the like are usedherein for the purpose of explanation only unless specifically indicatedotherwise.

The term “MRI visible” means that a device is visible, directly orindirectly, in an MRI image. The visibility may be indicated by theincreased SNR of the MRI signal proximate to the device (the device canact as an MRI receive antenna to collect signal from local tissue)and/or that the device actually generates MRI signal itself, such as viasuitable hydro-based coatings and/or fluid (typically aqueous solutions)filled channels or lumens.

The term “MRI compatible” means that a device is safe for use in an MRIenvironment and/or can operate as intended in an MRI environment, and,as such, if residing within the high-field strength region of themagnetic field, is typically made of a non-ferromagnetic MRI compatiblematerial(s) suitable to reside and/or operate in a high magnetic fieldenvironment.

The term “high-magnetic field” refers to field strengths above about 0.5T, typically above 1.0T, and more typically between about 1.5T and 10T.

The term “targeting cannula” refers to an elongate device, typicallyhaving a substantially tubular body that can be oriented to providepositional data relevant to a target treatment site and/or define adesired access path orientation or trajectory. At least portions of atargeting cannula contemplated by embodiments of the invention can beconfigured to be visible in an MRI image, thereby allowing a clinicianto visualize the location and orientation of the targeting cannula invivo relative to fiducial and/or internal tissue landscape features.Thus, the term “cannula” refers to an elongate device that can beassociated with a trajectory frame that attaches to a patient, but doesnot necessarily enter the body of a patient.

The term “imaging coils” refers to a device that is configured tooperate as an MRI receive antenna. The term “coil” with respect toimaging coils is not limited to a coil shape but is used generically torefer to MRI antenna configurations, loopless, looped, etc., as areknown to those of skill in the art. The term “fluid-filled” means thatthe component includes an amount of the fluid but does not require thatthe fluid totally, or even substantially, fill the component or a spaceassociated with the component. The fluid may be an aqueous solution, MRcontrast agent, or any material that generates MRI signal.

The term “two degrees of freedom” means that the trajectory framedescribed herein allows for at least translational (swivel or tilt) androtational movement over a fixed site, which may be referred to as aRemote Center of Motion (RCM).

The term “programmatically” refers to operations directed and/orprimarily carried out electronically by computer program modules, codeand instructions.

The term “fiducial marker” refers to a marker that can be identifiedusing electronic image recognition, electronic interrogation of MRIimage data, or three-dimensional electrical signals to define a positionand/or find the feature or component in 3-D space.

Embodiments of the present invention can be configured to guide and/orplace diagnostic or interventional devices and/or therapies to anydesired internal region of the body or object using MRI and/or in an MRIscanner or MRI interventional suite. The object can be any object, andmay be particularly suitable for animal and/or human subjects. Someembodiments can be sized and configured to place implantable DBS leadsfor brain stimulation, typically deep brain stimulation. Someembodiments can be configured to deliver tools or therapies thatstimulate a desired region of the sympathetic nerve chain. Other usesinside or outside the brain include stem cell placement, gene therapy ordrug delivery for treating physiological conditions. Some embodimentscan be used to treat tumors. Some embodiments can be used for RFablation, laser ablation, cryogenic ablation, etc. In some embodimentsthe trajectory frame and/or interventional tools can be configured tofacilitate high resolution imaging via integral intrabody imaging coils(receive antennas), and/or the interventional tools can be configured tostimulate local tissue, which can facilitate confirmation of properlocation by generating a physiologic feedback (observed physicalreaction or via fMRI).

Some embodiments can be used to deliver bions, stem cells or othertarget cells to site-specific regions in the body, such as neurologicaltarget and the like. In some embodiments, the systems deliver stem cellsand/or other cardio-rebuilding cells or products into cardiac tissue,such as a heart wall via a minimally invasive MRI guided procedure,while the heart is beating (i.e., not requiring a non-beating heart withthe patient on a heart-lung machine). Examples of known stimulationtreatments and/or target body regions are described in U.S. Pat. Nos.6,708,064; 6,438,423; 6,356,786; 6,526,318; 6,405,079; 6,167,311;6,539,263; 6,609,030 and 6,050,992, the contents of which are herebyincorporated by reference as if recited in full herein.

Generally stated, some embodiments of the invention are directed to MRIinterventional procedures and provide interventional tools and/ortherapies that may be used to locally place interventional tools ortherapies in vivo to site-specific regions using an MRI system. Theinterventional tools can be used to define an MRI-guided trajectory oraccess path to an in vivo treatment site. Some embodiments of theinvention provide interventional tools that can provide positional dataregarding location and orientation of a tool in 3-D space with a visualconfirmation on an MRI. Embodiments of the invention may provide anintegrated system that may allow physicians to place interventionaldevices/leads and/or therapies accurately and in shorter durationprocedures over conventional systems (typically under six hours for DBSimplantation procedures, such as between about 1-5 hours).

In some embodiments, MRI can be used to visualize (and/or locate) atherapeutic region of interest inside the brain or other body locationsand utilize MRI to visualize (and/or locate) an interventional tool ortools that will be used to deliver therapy and/or to place a chronicallyimplanted device that will deliver therapy. Then, using thethree-dimensional data produced by the MRI system regarding the locationof the therapeutic region of interest and the location of theinterventional tool, the system and/or physician can make positionaladjustments to the interventional tool so as to align the trajectory ofthe interventional tool, so that when inserted into the body, theinterventional tool will intersect with the therapeutic region ofinterest. With the interventional tool now aligned with the therapeuticregion of interest, an interventional probe can be advanced, such asthrough an open lumen inside of the interventional tool, so that theinterventional probe follows the trajectory of the interventional tooland proceeds to the therapeutic region of interest. It should be notedthat the interventional tool and the interventional probe may be part ofthe same component or structure. A sheath may optionally form theinterventional tool or be used with an interventional probe or tool.

In particular embodiments, using the MRI in combination with local orinternal imaging coils and/or MRI contrast material that may becontained at least partially in and/or on the interventional probe orsheath, the location of the interventional probe within the therapeuticregion of interest can be visualized on a display or image and allow thephysician to either confirm that the probe is properly placed fordelivery of the therapy (and/or placement of the implantable device thatwill deliver the therapy) or determine that the probe is in theincorrect or a non-optimal location. Assuming that the interventionalprobe is in the proper desired location, the therapy can be deliveredand/or the interventional probe can be removed and replaced with apermanently implanted therapeutic device at the same location.

In some embodiments, in the event that the physician determines from theMRI image produced by the MRI and the imaging coils, which mayoptionally be contained in or on the interventional probe, that theinterventional probe is not in the proper location, a new therapeutictarget region can be determined from the MRI images, and the system canbe updated to note the coordinates of the new target region. Theinterventional probe is typically removed (e.g., from the brain) and theinterventional tool can be repositioned so that it is aligned with thenew target area. The interventional probe can be reinserted on atrajectory to intersect with the new target region. Although describedand illustrated herein with respect to the brain and the insertion ofdeep brain stimulation leads, it is understood that embodiments of thepresent invention may be utilized at other portions of the body and forvarious other types of procedures.

Exemplary embodiments are described below with reference to blockdiagrams and/or flowchart illustrations of methods, apparatus (systemsand/or devices) and/or computer program products. It is understood thata block of the block diagrams and/or flowchart illustrations, andcombinations of blocks in the block diagrams and/or flowchartillustrations, can be implemented by computer program instructions.These computer program instructions may be provided to a processor of ageneral purpose computer, special purpose computer, and/or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer and/orother programmable data processing apparatus, create means(functionality) and/or structure for implementing the functions/actsspecified in the block diagrams and/or flowchart block or blocks.

These computer program instructions may also be stored in acomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instructions whichimplement the functions/acts specified in the block diagrams and/orflowchart block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer-implemented process such that theinstructions which execute on the computer or other programmableapparatus provide steps for implementing the functions/acts specified inthe block diagrams and/or flowchart block or blocks.

Accordingly, exemplary embodiments may be implemented in hardware and/orin software (including firmware, resident software, micro-code, etc.).Furthermore, exemplary embodiments may take the form of a computerprogram product on a computer-usable or computer-readable storage mediumhaving computer-usable or computer-readable program code embodied in themedium for use by or in connection with an instruction execution system.In the context of this document, a computer-usable or computer-readablemedium may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. More specific examples (a non-exhaustive list) of thecomputer-readable medium would include the following: an electricalconnection having one or more wires, a portable computer diskette, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,and a portable compact disc read-only memory (CD-ROM). Note that thecomputer-usable or computer-readable medium could even be paper oranother suitable medium upon which the program is printed, as theprogram can be electronically captured, via, for instance, opticalscanning of the paper or other medium, then compiled, interpreted, orotherwise processed in a suitable manner, if necessary, and then storedin a computer memory.

Computer program code for carrying out operations of data processingsystems discussed herein may be written in a high-level programminglanguage, such as Java, AJAX (Asynchronous JavaScript), C, and/or C++,for development convenience. In addition, computer program code forcarrying out operations of exemplary embodiments may also be written inother programming languages, such as, but not limited to, interpretedlanguages. Some modules or routines may be written in assembly languageor even micro-code to enhance performance and/or memory usage. However,embodiments are not limited to a particular programming language. Itwill be further appreciated that the functionality of any or all of theprogram modules may also be implemented using discrete hardwarecomponents, one or more application specific integrated circuits(ASICs), or a programmed digital signal processor or microcontroller.

Embodiments of the present invention will now be described in detailbelow with reference to the figures. FIG. 1A is a block diagram of anMRI-guided interventional system 50, according to some embodiments ofthe present invention. The illustrated system 50 includes an MRI scanner75, a trajectory frame 100 attached to the body of a patient positionedwithin a magnetic field of the MRI scanner 75, a remote control unit400, a trajectory guide software module 300, and a clinician display500. The trajectory frame 100 supports a targeting cannula through whichvarious interventional devices may be inserted into the body of apatient. The frame 100 is adjustable such that the targeting cannula isrotatable about a pitch axis, about a roll axis, and such that thetargeting cannula can translate in X-Y directions. The frame 100 may beattached to the body of a patient directly or indirectly and may beconfigured to be attached to various parts of the body.

In some embodiments, a remote control unit 400 is provided to allow auser to remotely adjust the position of the targeting cannula. Thetrajectory guide software module 300 allows a user to define andvisualize, via display 500, a desired trajectory (D, FIGS. 17-18) intothe body of a patient of an interventional device extending through thetargeting cannula. The trajectory guide software module 300 also allowsthe user to visualize and display, via display 500, an actual trajectory(A, FIG. 17) into the body of an interventional device extending throughthe targeting cannula. The trajectory guide software module 300 displaysto the user the necessary positional adjustments (e.g., pitch axisrotation, roll axis rotation, X-Y translation) needed to align theactual trajectory of the targeting cannula with the desired trajectorypath (FIG. 1B). In addition, the user can view, via display 500, theactual trajectory changing as he/she adjusts the position of thetargeting cannula. The trajectory guide software module 300 isconfigured to indicate and display when an actual trajectory is alignedwith a desired trajectory.

FIG. 2A illustrates a burr hole 10 formed in the skull S of a patient. Aburr hole ring 12 overlies the burr hole 10 and is secured to the skullS. The illustrated burr hole ring 12 has a pair of ears 14, eachconfigured to receive a respective fastener (e.g., screw) therethroughfor securing the burr hole ring 12 to the skull. In the illustratedembodiment, the burr hole ring 12 is secured to the skull S via screws16. FIG. 2B illustrates a removable centering device 18 positioned onthe burr hole ring 12. The centering device 18 includes cut out portions20 that fit over the ears 14 of the burr hole ring 12. The function ofthe centering device 18 is to facilitate centering a trajectory frame100, described below, over the burr hole 10. After the frame 100 isattached to the skull of a patient, the centering device 18 is removed.

Referring to FIG. 3A, a trajectory frame 100 with a targeting cannula200 associated therewith is illustrated. The trajectory frame 100 allowsfor the adjustability (typically at least two degrees of freedom,including rotational and translational) and calibration/fixation of thetrajectory of the targeting cannula 200 and/or probe or tool insertedthrough the targeting cannula 200. The targeting cannula 200 includes anaxially-extending guide bore (not shown) therethrough that is configuredto guide the desired therapeutic or diagnostic tool, e.g., intra-brainplacement of a stimulation lead (or other type of device) in vivo, aswill be described below. Intra-brain placement of devices may includechronically placed devices and acutely placed devices. The trajectoryframe 100 may include fiducial markers 117 that can be detected in anMRI to facilitate registration of position in an image.

The illustrated trajectory frame 100 is configured to be mounted to apatient's skull around a burr hole ring (12, FIG. 1) and over a burrhole (10, FIG. 1), to provide a stable platform for advancing surgicaldevices, leads, etc. in the brain. The frame 100 includes a base 110, ayoke, 120, a platform 130, and a plurality of actuators 140 a-140 d. Thebase 110 has a patient access aperture 112 formed therein, asillustrated. The base 110 is configured to be secured (directly orindirectly) to the skull of a patient such that the patient accessaperture 112 overlies the burr hole 10 in the patient skull. The patientaccess aperture 112 is centered over the burr hole 10 via the removablecentering device 18. The yoke 120 is movably mounted to the base 110 andis rotatable about a roll axis RA. A roll actuator 140 a is operablyconnected to the yoke 120 and is configured to rotate the yoke 120 aboutthe roll axis RA, as will be described in detail below. In someembodiments, the yoke 120 has a range of motion about the roll axis RAof about seventy degrees (70°). However, other ranges, greater andlesser than 70°, are possible, e.g., any suitable angle typicallybetween about 10°-90°, 30°-90°, etc. The illustrated platform 130 ismovably mounted to the yoke 120 and is rotatable about a pitch axis PA.In some embodiments, the platform 130 has a range of motion about thepitch axis PA of about seventy degrees (70°). However, other ranges,greater and lesser than 70°, are possible, e.g., any suitable angletypically between about 10°-90°, 30°-90°, etc.

FIGS. 3B-3E are side view, schematic illustrations of the trajectoryframe being secured to the skull of a patient. FIG. 3B illustrates useof the centering device 18 to align the frame 100 relative to the burrhole 10. In FIG. 3C, the frame 100 is secured to the skull withfasteners and such that the patient access aperture 112 in the base 110is centered around the centering device 18. In FIG. 3D, the yoke 120 isrotated out of the way such that the centering device 18 can be removed.In FIG. 3E, the targeting cannula 200 is moved to an extended positionand locked in the extended position via prongs 208.

The platform 130 includes an X-Y support table 132 that is movablymounted to the platform 130. The X-Y support table 132 is configured tomove in an X-direction and Y-direction relative to the platform 130. AnX-direction actuator 140 c is operably connected to the platform 130 andis configured to move the X-Y support table 132 in the X-direction. AY-direction actuator 140 d is operably connected to the platform 130 andis configured to move the X-Y support table 132 in the Y-direction. Apitch actuator 140 b is operably connected to the platform 130 and isconfigured to rotate the platform 130 about the pitch axis PA, as willbe described in detail below.

The actuators 140 a-140 d are configured to translate and/or rotate theframe. The targeting cannula 200 is configured to translate in responseto translational movement of the X-Y support table 132 and to rotate inresponse to rotational movement of the yoke 120 and platform 130 todefine different axial intrabody trajectories extending through thepatient access aperture 112 in the frame base 110.

The actuators 140 a-140 d may be manually-operated devices, such asthumbscrews, in some embodiments. The thumbscrews can be mounted on theframe 100 or may reside remotely from the frame 100. A user may turn theactuators 140 a-140 d by hand to adjust the position of the frame 100and, thereby, a trajectory of the targeting cannula 200. In otherembodiments, the actuators 140 a-140 d are operably connected to aremote control unit 400 (FIGS. 9-10) via a respective plurality ofnon-ferromagnetic, flexible drive shafts or control cables 150 a-150 d.The remote control unit 400 includes a plurality of position controls402 a-402 d, and each cable 150 a-150 d is operably connected to arespective position control 402 a-402 d and to a respective actuator 140a-140 d. Movement of a position control 402 a-402 d operates arespective actuator 140 a-140 d via a respective control cable 150 a-150d, as will be described below. The cables 150 a-150 d may extend asuitable distance (e.g., between about 1-4 feet, etc.) to allow aclinician to adjust the settings on the trajectory frame 100 withoutmoving a patient and from a position outside the bore of a magnet (wheresuch magnet type is used) associated with an MRI scanner.

Referring to FIGS. 6-7, the base 110 includes a plurality of locations112 for attaching the base 110 to a skull of a patient via fasteners.Each location may include two or more adjacent apertures 114. Eachaperture 114 is configured to receive a fastener (e.g., a screw, rod,pin, etc.) therethrough that is configured to secure the base 110 to theskull of a patient.

The base 110 also includes MRI-visible fiducial markers 117 that allowthe location/orientation of the frame 100 to be determined within an MRIimage during an MRI-guided procedure. In the illustrated embodiment, thefiducial markers 117 have a torus or “doughnut” shape and are spacedapart. However, fiducial markers having various shapes and positioned atvarious locations on the frame 100 may be utilized.

The base 110 also includes a pair of spaced apart arcuate arms 116, asillustrated in FIG. 11. The yoke 120 is pivotally attached to pivotpoints 113 for rotation about the roll axis RA. The yoke 120 engages andmoves along the base arcuate arms 116 when rotated about the roll axisRA. In the illustrated embodiment, one of the base arcuate arms 116includes a thread pattern 118 formed in (e.g., embossed within, machinedwithin, etc.) a surface 116 a thereof. However, in other embodiments,both arms 116 may include respective thread patterns. The roll actuator140 a includes a rotatable worm 142 with teeth that are configured toengage the thread pattern 118, as illustrated in FIG. 5. As the worm 142is rotated, the teeth travel along the thread pattern 118 in the arcuatearm surface 116 a. Because the base 110 is fixed to a patient's skull,rotation of the roll actuator worm 142 causes the yoke 120 to rotateabout the roll axis RA relative to the fixed base 110. Rotation aboutroll axis RA is illustrated in FIGS. 4-5. For example, in FIG. 5, theyoke 120 is rotated about the roll axis RA sufficiently to allow removalof the centering device 18.

Referring to FIG. 12, the yoke 120 includes a pair of spaced apartupwardly extending, arcuate arms 122. The platform 130 engages and movesalong the yoke arcuate arms 122 when rotated about the pitch axis PA. Inthe illustrated embodiment, one of the yoke arcuate arms 122 includes athread pattern 124 formed in (e.g., embossed within, machined within,etc.) a surface 122 a thereof. However, in other embodiments, both arms122 may include respective thread patterns. The pitch actuator 140 bincludes a rotatable worm 146 with teeth 148 that are configured toengage the thread pattern 124. As the worm 146 is rotated, the teeth 148travel along the thread pattern 124 in the arcuate arm surface 122 a.Because the base 110 is fixed to a patient's skull, rotation of thepitch actuator worm 146 causes the platform 130 to rotate about thepitch axis PA relative to the fixed base 110.

As illustrated in FIG. 19A, the X-Y support table 132 includes a movingplate 134 that moves in both the X-direction and Y-direction. TheX-direction actuator 140 c, when rotated, causes translational movementof the moving plate 134 along the X-axis. For example, clockwiserotation of the X-direction actuator 140 c causes movement toward the“−X direction (i.e., to the left) in FIG. 19A; and counterclockwiserotation of the X-direction actuator 140 c causes movement along the +Xdirection (i.e., to the right) in FIG. 19A, etc. The Y-directionactuator 140 d, when rotated, causes translational movement of themoving plate 134 along the Y-axis. For example, clockwise rotation ofthe Y-direction actuator 140 d causes movement along the −Y direction(i.e., out of the paper) in FIG. 19A; and clockwise rotation of theY-direction actuator 140 d causes movement along the +Y direction (i.e.,into the paper) in FIG. 19A. In the illustrated embodiment, graduationscales 136, 137 are provided on the platform adjacent the moving plate134. The moving plate 134 includes a pair of marks or indicators 138that provide visual indication of X-Y movement of the moving plate 134.FIG. 19B illustrates X-Y translation of an X-Y support table 132,according to some embodiments of the present invention.

Various internal drive mechanisms may be utilized for causingtranslational movement of the moving plate 134 in response to userrotation of the X-direction actuator 140 c and the Y-direction actuator140 d. For example, drive belts, linkages, gears, or worm drives may beutilized, as would be understood by one skilled in the art of X-Ytables. Embodiments of the present invention are not limited to anyparticular mechanism for translating the X-Y table 132 along the X and Ydirections. FIG. 19C is partial perspective view of an X-Y supporttable, according to some embodiments, with elements removed to revealinternal components of an X-direction actuator 140 c and Y-directionactuator 140 d.

As illustrated in FIG. 3A, the roll actuator 140 a, pitch actuator 140b, X-direction actuator 140 c, and Y-direction actuator 140 d eachextend outwardly from the frame 100 along the same direction (e.g.,upwardly from the platform 130). This configuration facilitates easyconnection of the control cables 150 a-150 d to the actuators 140 a-140d (where used) and also facilitates bundling of the cables 150 a-150 dto reduce clutter or provide ease of handling and set-up. Embodiments ofthe present invention are not limited to the illustrated embodiment,however. The actuators 140 a-140 d may extend in various directions andthese directions may be different from each other. In addition, theactuators 140 a-140 d may extend along the same direction from theframe, but in a different direction than that illustrated in FIG. 3A.For example, FIG. 16 illustrates an embodiment where the actuators 140a-140 d extend from a common side of the platform 130.

Referring to FIGS. 9 and 10A-10C, the remote control unit 400 of theillustrated system 50 includes a plurality of manually-operable positioncontrols 402 a-402 d. Specifically, the control unit 400 includes a rolladjustment control 402 a, a pitch adjustment control 402 b, anX-direction adjustment control 402 c, and a Y-direction adjustmentcontrol 402 d. A roll control cable 150 a is operably connected to theroll adjustment control 402 a and to the roll actuator 140 a such thatmovement of the roll adjustment control 402 a operates the roll actuator140 a via the roll control cable 150 a. A pitch control cable 150 b isoperably connected to the pitch adjustment control 402 b and to thepitch actuator 140 b such that movement of the pitch adjustment control402 b operates the pitch actuator 140 b via the pitch control cable 150b. An X-direction control cable 150 c is operably connected to theX-direction control 402 c and to the X-direction actuator 140 c suchthat movement of the X-direction adjustment control 402 c operates theX-direction actuator 140 c via the X-direction control cable 150 c. AY-direction control cable 150 d is operably connected to the Y-directioncontrol 402 d and to the Y-direction actuator 140 d such that movementof the Y-direction adjustment control 402 d operates the Y-directionactuator 140 d via the Y-direction control cable 150 d.

In the illustrated embodiment, each of the position controls 402 a-402 dis a thumbwheel control that can be rotated by a user's finger inclockwise and counterclockwise directions. Rotation of each thumbwheel402 a-402 d by a user causes corresponding axial rotation of arespective control cable 150 a-150 d and corresponding axial rotation ofa respective actuator 140 a-140 d.

FIG. 10B illustrates position controls, according to additionalembodiments of the present invention, that utilize two thumbwheels. Onethumbwheel 402 a′ is for “fine” adjustments; the other thumbwheel 402 a″is for “gross” adjustments. The amount of fine and gross adjustment iscorrelated to the diameter of each thumbwheel, as would be understood byone skilled in the art. FIG. 10C illustrates a position control 402 a′″,according to additional embodiments of the present invention, thatindicates incremental X-Y variable markings.

In the illustrated embodiment, locking mechanisms 404 a-404 c areassociated with the thumbwheels 402 a-402 d and prevent user rotationthereof when in a locked position. For example, a locking mechanism 404a is operably associated with the roll adjustment control 402 a and isconfigured to prevent rotation thereof by a user when in a “locked”position. Locking mechanism 404 b is operably associated with pitchadjustment control 402 b and is configured to prevent rotation thereofby a user when in a “locked” position. Locking mechanism 404 c isoperably associated with X-direction control 402 c and Y-directioncontrol 402 d and is configured to prevent rotation of X-directioncontrol 402 c and Y-direction control 402 d by a user when in a “locked”position.

Each control cable 150 a-150 d can have a geometrically shaped rigid end151 a-151 d that is configured to removably engage a free end of arespective actuator 140 a-140 d. As illustrated in FIG. 16, therespective free ends 141 a-141 d of the actuators 140 a-140 d may have aslot 143 formed therein that is configured to removably receive arespective cable end. Exemplary cable end shapes include, but are notlimited to, “L” shapes, “U” shapes, square shapes, rectangular shapes,oval/circular shapes, and other polygonal shapes. Each cable end hassufficient rigidity such that axial rotation of the cable causes thecable free end to impart rotational motion to a respective actuator.FIG. 15 illustrates the free end of cable 150 b having a connector 151 bwith a geometric shape attached thereto that is configured to matinglyengage a respective slot 143 in actuator 140 b, according to otherembodiments of the present invention.

In some embodiments, the free end of an actuator 140 a-140 d may beconfigured to receive only a specific one of the control cables 150a-150 d. For example, in FIG. 15, the connector 151 b may not fit withinthe slots 143 of any of the other actuators. As such, a control cablecannot be inadvertently connected to the wrong actuator. For example,the roll adjustment actuator free end 141 a may be configured to onlyreceive the free end 151 a of the control cable 150 a associated withthe roll control 402 a. Similarly, the pitch adjustment actuator freeend 141 b may be configured to only receive the free end 151 b of thecontrol cable 150 b associated with the pitch control 402 b.

Each control cable 150 a-150 d also has a flexible elastomeric (e.g.,silicone, rubber, etc.) collar 154 a-154 d that is configured tosurround a respective actuator 140 a-140 d and maintain engagement ofthe respective cable end 151 a-151 d within the respective actuator.Each elastomeric collar 154 a-154 d is configured to prevent removal ofa cable by a user, for example, as a result of inadvertent tugging onthe cable by a user, or by movement of the remote control unit 400. Eachof the illustrated collars 154 a-154 d can be rolled or folded back thenreleased to cover and conformably compress against an actuator to holdthe end of a respective cable in position. Each collar 154 a-154 d canthen be pushed back to easily release the cable from the actuator. Inthe illustrated embodiment, each actuator 140 a-140 d has acircumferential groove 145 configured to receive a correspondingcircumferential ridge 156 of a collar 154 a-154 d in mating relationtherewith.

FIG. 16B illustrates remote control cable end 151 a about to be insertedinto slot 143 in the actuator free end 141 a. The cable end 151 a isinserted into the slot 143 and then the elastomeric collar 154 a isfitted around the actuator 140 a such that the circumferential ridge 156engages the circumferential actuator groove 145, as illustrated in FIG.16C. Because of the elastomeric nature of the collar 154 a, the collarsnuggly fits the actuator 140 a and retains the cable end 151 a withinslot 143. To remove the cable end 151 a, the circumferential ridge 156is pulled out of the groove 145 and the collar 154 a is rolled back onitself as illustrated in FIGS. 16D-16E.

Embodiments of the present invention are not limited to the illustratedelastomeric collars 154 a-154 d. Other ways of retaining the cable ends151 a-151 d within respective actuators 140 a-140 d may be utilizedwithout limitation.

In some embodiments, the actuators 140 a-140 d are color coded such thateach actuator has a different respective color for easy identificationby a user. For example, the roll actuator 140 a may be colored red andthe pitch actuator 140 b may be colored yellow such that a user caneasily identify the two respective actuators when positioning the frame100. In some embodiments, the elastomeric collars 154 a-154 d may alsobe color coded so as to match the color of a respective actuator 140a-140 d. In some embodiments, the cable ends 151 a-151 d may also becolor coded so as to match the color of a respective actuator 140 a-140d.

In some embodiments of the present invention, the control cables 150a-150 d are formed of NITINOL or other MR-compatible materials. One ormore portions of the frame 100 and the targeting cannula 200 may also beformed of NITINOL or other MR-compatible (non-paramagnetic) materials.

FIG. 31 illustrates a patient positioned within an MRI scanner and auser utilizing the remote control apparatus 400 and display monitors toadjust the trajectory a targeting cannula, according to some embodimentsof the present invention.

FIGS. 32A-32C illustrate a remote control unit 800 for remotelycontrolling the positioning actuators of the frame of FIG. 3A, accordingto other embodiments of the present invention. The illustrated remotecontrol unit 800 includes a separate, multi-rod control device 802 a-802d for each respective actuator 140 a-140 d. Each of the control devices802 a-802 d can be identical in structure and, as such, only one will bedescribed in detail hereinafter. However, each control device 802 a-802d may be color coded with a color different from the other controldevices 802 a-802 d, and each control device 802 a-802 d may havedifferent lengths, shapes or sizes for ease of assembly and/oroperation. Moreover, each control device 802 a-802 d may be color codedso as to match the color of a respective actuator 140 a-140 d.

Each control device 802 a-802 d includes a pair of elongated rods 804,806 (e.g., solid, MRI-compatible rods) joined at respective ends via aflexible member such as a cable 807, as illustrated. The rods 804, 806may be formed of wood, polymeric material, or other suitable relativelylightweight MM-compatible material. In addition, the rods 804, 806 arenot required to be solid.

The cable 807 is relatively short in length relative to the length ofrods 804, 806 and serves as a universal joint to allow the two rods 804,806 to rotate even when oriented transverse to each other. For example,the cable 807 may be between about one quarter inch and about one inch(0.25″-1″) in length. However, embodiments of the present invention arenot limited to this range for the length of cable 807; cable 807 mayhave other lengths. In some embodiments, the cable 807 is anMRI-compatible cable (e.g., NITINOL, etc.). In the illustratedembodiment, the distal end 804 b of rod 804 is joined to the proximalend 806 a of rod 806 via cable 807. The cable 807 may be joined to rods804, 806 in any of various ways including, but not limited to, viaadhesives, via fasteners, via threaded connections, etc.

The proximal end 804 a of rod 804 includes an endcap 808 securedthereto. The endcap 808 may be formed from tactile material tofacilitate rotation of rod 804 by a user. A knob or other device thatfacilitates rotation may be secured to the proximal end of rod 804 inlieu of endcap 808, in other embodiments. In operation, a user rotatesthe proximal end 804 a of rod 804 in a clockwise or counterclockwisedirection to correspondingly rotate actuator 140 a.

The distal end 806 b of rod 806 is joined to actuator 140 a via aflexible member such as a cable 810, as illustrated. The cable 810 isrelatively short in length relative to the length of rod 806 and servesas a universal joint to allow rod 806 to rotate even when orientedtransverse to actuator 140 a. In some embodiments, the cable 810 is anMRI-compatible cable. For example, the cable 810 may be between aboutone half inch and about one and one half inch (0.5″-1.5″) in length.However, embodiments of the present invention are not limited to thisrange for the length of cable 810; cable 810 may have other lengths.

Cable 810 may be joined to rod 806 in any of various ways including, butnot limited to, via adhesives, via fasteners, via threaded connections,etc. The free end of cable 810 may have a rigid, geometrical shape, asdescribed above with respect to the embodiments of cables 150 a-150 d,and may be configured to engage a slot within the actuator 140 a, asdescribed above. An elastomeric collar, as described above with respectto FIGS. 16A-16E, may or may not be necessary to retain the free end ofcable 810 within actuator 140 a. In the illustrated embodiment, anelastomeric collar is not utilized. When used, an elastomeric collar canalso be color coded to the actuator and/or control device rods 804, 806.

In the illustrated embodiment, the control devices 802 a-802 d aresupported by a pair of spaced apart separator devices 812. Eachseparator device 812 includes a plurality of substantially parallel,spaced apart bores passing therethrough that are configured to receiveeach of the rods 804 for the respective control devices 802 a-802 d. Theseparator devices 812 are configured to maintain the rods 804 insubstantially parallel, spaced apart relationship, as illustrated. Inthe illustrated embodiment, only rods 804 pass through the two separatordevices 812. However, embodiments of the present invention are notlimited to the illustrated use, configuration, location, or number ofseparation devices 812. In addition, although shown as two rods formingeach control device 802 a-802 d, they may include three or more spacedapart rods (not shown), or only a single rod (not shown). Moreover,other types of devices may be utilized without limitation.

Referring to FIGS. 14 and 19, an elongated tubular member 204 extendsthrough the platform 130 and yoke 120 and is secured to the X-Y supporttable 132. The targeting cannula 200 is slidably secured within thetubular member 204 and is movable between extended and retractedpositions. FIGS. 3A-3D and 4-6 illustrate the targeting cannula 200 in aretracted position above the burr hole 10 and FIGS. 3E and 8A illustratethe targeting cannula 200 in an extended position. The tubular member204 is configured to lock the targeting cannula 200 in an extendedposition and in a retracted position, as illustrated in FIG. 14. Thetubular member 204 has a pair of radially opposed elongated,axial-extending slots 206, as illustrated. The ends 206 a, 206 b of eachslot 206 include a transverse portion 207 that is configured to retainthe targeting cannula 200 in respective extended and retractedpositions. The targeting cannula 200 includes a respective pair ofradially extending prongs 208, as illustrated. Each prong 208 cooperateswith a respective slot 206. When the targeting cannula 200 is movedupwardly to the retracted position, the targeting cannula 200 is rotatedslightly (or the tubular member 204 is rotated slightly) such thatprongs 208 each engage a respective transverse portion 207. When soengaged, the targeting cannula 200 is retained in the retractedposition. When the targeting cannula 200 is moved downwardly to theextended position, the targeting cannula 200 is rotated slightly (or thetubular member 204 is rotated slightly) such that prongs 208 each engagea respective transverse portion 207. When so engaged, the targetingcannula 200 is retained in the extended position.

Embodiments of the present invention are not limited to the illustratedconfiguration or number of slots 206 in the tubular member 204 or to thenumber of prongs 208 extending from the targeting cannula 200. Forexample, the targeting cannula 200 may have a single prong 208 that isconfigured to cooperate with a respective single slot 206 in the tubularmember 204. In addition, slot 206 may have a different configurationthan illustrated.

Referring to FIGS. 20-26, a depth stop 210 with a removable sheath 212inserted and secured therein is illustrated. The illustrated depth stop210 has a generally cylindrical configuration with opposite proximal anddistal ends 210 a, 210 b and is adapted to be removably secured withinthe proximal end 204 a of the tubular member 204. The depth stop 210 isconfigured to limit a distance that the sheath 212 extends into the bodyof a patient when the depth stop is inserted within the tubular member204. The sheath 212 is configured to receive and guide an elongatedinterventional device therethrough, as will be described below. Thesheath 212 includes opposing tabs 214 a, 214 b that, when pulled apart,cause the sheath 212 to peel away for removal from the targeting cannula200.

Prior to insertion within the tubular member 204, the distal end 210 bof the depth stop 210 is positioned adjacent to a mark 215 on theremovable sheath 212, as illustrated in FIG. 21. Locking screw 216 isthen tightened to prevent axial movement of the sheath 212 relative tothe depth stop 210. An elongate location verification probe 217, such asan imaging probe or rigid stylet, is then inserted within the sheath 212as illustrated in FIG. 21.

Referring to FIGS. 22-23, the opposing tabs 214 a, 214 b of the sheathare pulled apart slightly, and the depth stop 210, sheath 212 andimaging probe 217 are inserted into the proximal end 204 a of tubularmember 204. When so inserted, as illustrated in FIG. 23, the sheath 212and imaging probe 217 pass through the axial bore of the targetingcannula 200. The imaging probe 217 is then utilized to verify that thedistal end 212 b of the sheath 212 is positioned at the correct locationwithin the body of a patient. Upon verifying that the sheath 212 isaccurately positioned, the imaging probe 217 is removed (FIG. 23).

The probe 217 extending through the targeting cannula guide bore caninclude at least one electrode (which may include a coil winding) on adistal tip portion thereof. The electrode can be a recording and/orstimulating electrode. The electrode can be configured to deliver testvoltages for physiologic confirmation of location/efficacy that can bedone by fMRI or by feedback from a non-anesthetized patient. Thus, apatient can be stimulated with an interventional probe (the stimulationmay be via a transducer on a distal tip portion of the probe), to helpconfirm that the interventional probe is in the correct location (i.e.,confirm proper location via anatomical as well as provide physiologicinformation and feedback). During (and typically substantiallyimmediately after) stimulation from the interventional probe, thephysician can monitor for a physiologic response from the patient thatcan be observed either directly from the patient as a physical responseor via an fMRI-visible response.

The elongate probe 217 can be MRI-visible and may optionally beconfigured to define an MRI antenna. The system 50 can be configured toallow for real-time tracking under MRI, with an SNR imaging improvementin a diameter of at least 1-10 mm surrounding the probe.

Next, a locking mechanism 220 is removably secured to the proximal end210 a of the depth stop 210. The locking mechanism 202 includes opposingaxially extending slots 221, as illustrated. The portions of the sheath212 that have been peeled away extend through these slots asillustrated. The locking mechanism 220 is secured to the depthstop/tubular member via locking screw 222.

The targeting cannula 200 is now ready to receive an interventionaldevice therein. As illustrated in FIG. 25, an interventional device 230,such as a brain stimulation lead, is inserted into the locking mechanismand through the removable sheath 212. A locking screw 224 is tightenedto secure the interventional device 230 and prevent axial movementthereof.

The targeting cannula 200 can be MRI-visible. In some particularembodiments, the cannula 200 may optionally comprise a plurality ofspaced apart microcoils configured to provide data used to provide 3-Ddimensional data in MRI 3-D space, such as a trajectory, or 3-D spatialcoordinates of position of the cannula 200. The microcoils can eachprovide data that can be correlated to a three-dimensional (X, Y, Z)position in 3-D space in the body. The microcoils can be incommunication with the MRI scanner, and tracking sequences can begenerated and data from one or more of the MRI scanner channels can beused to define positional 3-D positional data and a trajectory thereof.

In some particular embodiments, the progress of the cannula 200 and/orinterventional probe 230 or other device may optionally be tracked insubstantially real-time as it advances to the target via the coils(similar ones of which may also or alternatively be on or in the probeor other device) and/or antenna. However, real-time tracking may not bedesired in some embodiments.

In some embodiments, the cannula 200 can include at least one axiallyextending fluid-filled hollow lumen (FIG. 8B) or closed channel withfluid that can generate MRI signal that can be detected by an MRIscanner and/or by an internal MRI antenna incorporated on and/or intothe cannula 200 that can increase the SNR of the fluid to increase itsvisibility in an MRI. The fluid may be an aqueous solution (able toresonate at the proton frequency). The cannula 200 can include anaxially extending, relatively thin segment, which creates a highcontrast MRI image (a segment filled with water or other suitablecontrast solution filled section/lumen). The thickness of the segmentmay be between about 0.25-15 mm (and the segment can have a tubularshape with a diameter or may define another cross-sectional shape suchas a square section). The cannula 200 may include MRI imaging coils toincrease the signal from the high contrast fluid. See, e.g., co-pendingU.S. patent application Ser. No. 12/066,862, which is incorporated hereby reference in its entirety.

As illustrated in FIGS. 26A and 26B, the interventional device 230 ispositioned at the desired location within the body of a patient. Theremovable sheath 212 is then completely removed by pulling apart theopposing tabs 214 a, 214 b. A clamp 240 (FIG. 27) is inserted within theburr hole ring 12 that grips the interventional device 230 to preventinadvertent removal of the interventional device 230 from the body ofthe patient. The clamp 240 is secured to the burr hole ring 12. Theframe 100 can then be removed from the body of the patient, leavingbehind only the interventional device 230 that has been inserted intothe patient body.

FIGS. 28A-28G are side view, schematic illustrations of the trajectoryframe 100 illustrating an exemplary series of operations for theinsertion of interventional devices within the body of a patient via thetargeting cannula 200. In FIG. 28A, the locking mechanism 220, depthstop 210, and removable sheath 212 are positioned within the targetingcannula 200. In FIG. 28B, an interventional device, e.g., lead 230, isinserted within the sheath 212 and into the brain of the patient. Thelocking mechanism 220 secures the lead against axial movement (FIG.28C). The targeting cannula 200 is then retracted (FIGS. 28D-28E). Thelocking mechanism 220 is unlocked (FIG. 28F) and the frame 100 isremoved from the skull of the patient (FIG. 28G).

In some embodiments of the present invention, a video imaging device(e.g., a fiber optic probe with visual access to the burr hole 10 and/ortrajectory frame 100 in communication with a camera and display in aclinician workstation) 500 for viewing the burr hole 10 is removablysecured to the frame 100 or to the targeting cannula tubular member 204via a bracket 502. For example, as illustrated in FIG. 13A, a bracket502 is secured to the targeting cannula tubular member 204. Theillustrated bracket 502 is configured to adjustably slide axially alongthe tubular member 204 for positioning. The illustrated bracket 502includes a sleeve 504 that is configured to slidably receive an imagingdevice 500 therein. Threaded locking device 506 is configured to securethe imaging device 500 in position within the sleeve 504 for positioningof the imaging device 500 relative to the body of a patient. A clinicianviews images captured by the video imaging device 500 via a monitor, asillustrated in FIG. 13B.

In the illustrated embodiment of FIG. 29, a sterile drape 600 isprovided for holding the remote control unit 400. The drape 600 isconfigured to be positioned near the body of a patient and includes apocket 602 configured to removably receive the remote control unit 400therein. The drape 600 also includes an aperture 604 through which thecables 150 a-150 b extend from the remote control unit 400 to the frame100. In the illustrated embodiment, the drape 600 is attached to themagnet housing M of an MRI scanner system.

In some embodiments, the control cables 150 a-150 d are configured tohave a limited length. Accordingly, as illustrated in FIG. 30, a safetylanyard 700 may be attached to the remote control unit 400 and to arigid object to prevent inadvertent detachment of the control cables 150a-150 d from the frame actuators 140 a-140 d caused by moving the remotecontrol unit 400 too far from the frame 100.

Operations associated with a typical surgical procedure using thetrajectory frame 100, according to some embodiments of the presentinvention, will now be described. These operations relate to deep brainstimulation procedures. Embodiments of the present invention are notlimited to use with deep brain stimulation procedures, however.

Initially, a patient is placed within an MR scanner and MR images areobtained of the patient's head that visualize the patient's skull,brain, fiducial markers and ROI (region of interest or targettherapeutic site). The MR images can include volumetric high-resolutionimages of the brain. To identify the target ROI, certain knownanatomical landmarks can be used, i.e., reference to the AC, PC and MCPpoints (brain atlases give the location of different anatomies in thebrain with respect to these point) and other anatomical landmarks. Thelocation of the burr hole 10 may optionally be determined manually byplacing fiducial markers on the surface of the head or programmaticallyby projecting the location in an image.

Images in the planned plane of trajectory are obtained to confirm thatthe trajectory is viable, i.e., that no complications with anatomicallysensitive areas should occur. The patient's skull is optically ormanually marked in one or more desired locations to drill the burr hole.The burr hole 10 is drilled and a burr hole ring 12 is affixed to theskull overlying the burr hole.

The trajectory frame 100 is then fixed to the skull of the patient andthe targeting cannula 200 is properly fitted thereto. A localizationscan is obtained to determine/register the location of the targetingcannula 200, in direct orientation of the trajectory frame 100. Thesettings to which the trajectory frame 100 should be adjusted areelectronically determined so that the targeting cannula 200 is in thedesired trajectory plane. Frame adjustment calculations are provided toa clinician who can manually or electronically adjust the orientation ofthe frame 100. The desired trajectory plane is confirmed by imaging inone or more planes orthogonal to the desired trajectory plane.

Once the targeting cannula 200 has the desired trajectory plane, theprobe 217 and delivery sheath 212 are advanced through the targetingcannula 200. The advancement of the probe 217 is monitored by imaging toverify that the probe will reach the target accurately. If the probe 217and delivery sheath 212 are at the desired target, the sheath is left inplace and the probe 217 is removed. The sheath 212 will now act as thedelivery cannula for the implantable lead 230.

If the probe 217 and delivery sheath 212 are not at the desired/optimallocation, a decision is made as to where the probe 217 and deliverysheath 212 need to be. The sheath 212 and the probe 217 are withdrawnfrom the brain. The trajectory frame 100 is adjusted accordingly via theactuators 140 a-140 d and the probe 217 and delivery sheath 212 arere-advanced into the brain. Once the probe 217 and delivery sheath 212are at the desired location, the probe 217 is removed and the deliverysheath is left in place. The lead 230 is then advanced to the targetlocation using the sheath 212 as a guide. The location of the lead isconfirmed by reviewing an image, acoustic recording and/or stimulation.The sheath 212 is then removed, leaving the lead in place.

It is contemplated that embodiments of the invention can provide anintegrated system 50 that may allow the physician to place theinterventional device/leads accurately and in short duration of time. Insome embodiments, once the burr hole is drilled, and the trajectoryframe is fixed to the skull; the trajectory frame is oriented such thatthe interventional device advanced using the trajectory frame followsthe desired trajectory and reaches the target as planned in preoperativesetup imaging plans. As described herein, the system 50 can employhardware and software components to facilitate an automated orsemiautomated operation to carry out this objective.

With reference to FIGS. 33-38, a trajectory guide frame 1100 accordingto further embodiments of the present invention is shown therein. Theframe 1100 can be generally constructed and used in the same or similarmanner as discussed above with regard to the trajectory guide frame 100,except as discussed herein. The frame 1100 includes a base 1110, a yoke1120, a platform 1130, a targeting cannula 1200 (FIG. 38), and a tubulartrajectory guide member 1204 corresponding to the components 110, 120,130, 200 and 204, respectively, of the frame 100. The targeting cannula1200 has a guide lumen tube 1258 (FIG. 38) to receive an interventionaldevice. The targeting cannula 1200 can slide up and down in the passage1204C (FIG. 38) of the targeting cannula guide member 1204 as discussedabove with the targeting cannula 200 and the guide member 204. The frame1100 further includes a scope bracket 1502. The bracket 1502 can be usedto selectively and adjustably secure an imaging device, a lighttransmission scope or other suitable device.

The light transmission scope can include an optical fiber scope 1552connected to a video camera 1551 (schematically illustrated in FIG. 33),for example, which is in turn connected to a display such as the display500 (FIGS. 1 and 33). The fiber scope 1552 may include an inner tube1554 containing a bundle of optical fibers, and an outer tubular jacket1556 surrounding a portion of the inner tube 1554. A lens 1558 can beprovided at the terminal end of the inner tube 1554. The optical fiberscan transmit light to the camera 1551. Optical fibers may also beprovided in the inner tube 1554 to transmit light from a light source1553 to the terminal end of the fiber scope 1552 to illuminate the localregion (e.g., burr hole) observed via the lens 1558.

Turning to the bracket 1502 in more detail and with reference to FIG.36, the bracket 1502 includes a frame mount collar or portion 1504, acamera probe mount portion 1506, and a connector leg 1508 joining theportions 1504, 1506. A lock screw 1510A is provided in the frame mountportion 1504 and a lock screw 1510B is provided in the camera probemount portion 1506. The frame mount portion 1504 includes opposed clamparms 1512. Opposed projections 1514A and 1514B extend inwardly from theclamp arms 1512. A bore 1516 (FIG. 38) is defined in the bracket 1502and has an upper section 1516A and a lower section 1516B, the lowersection 1516B having a reduced diameter as compared to that of the uppersection 1516A.

Opposed arcuate, circumferential mount grooves 1204A and 1204B (FIGS. 36and 37) are defined in the outer surface of the targeting cannula guidemember 1204. The clamp arms 1512 are engaged about the guide member 1204with the projections 1514A and 1514B seated in or mating with thegrooves 1204A and 1204B, respectively. In this manner, the bracket 1552is secured to the guide member 1204 beneath the yoke 1120. The bracket1502 may be further secured to the guide member 1204 by tightening thelock screw 1510A.

In use, the fiber scope 1552 is inserted through the bore 1516 such thatthe outer jacket 1556 is received in the bore section 1516A, the innertube 1554 is received in the bore section 1516B, and the lens 1558 isdirected at the patient access aperture 1112 and the burr hole, whenpresent. The fiber scope 1552 may be secured in the bracket 1502 bytightening the lock screw 1510B.

The bracket 1502 can be rotated in each of opposed rotation directionsR1 and R2 (FIGS. 35 and 37) about the trajectory axis TCA (defined bythe guide bore or lumen 1250 (FIG. 37) of the targeting cannula 1200(FIG. 38)) by rotating the clamp arms 1512 circumferentially about theguide member 1204. The relative dimensions of the projections 1514A,1514B and the grooves 1204A, 1204B may permit the bracket 1502 to rotatewithin a prescribed range. The prescribed range of rotation can beselected to prevent or reduce the risk of interference between thebracket 1502 and the yoke 1120. According to some embodiments, the rangeof rotation is less than 180 degrees on each side of the yoke 1120.According to some embodiments, the range of rotation is in the range offrom about 10 to 80 degrees on each side of the yoke 1120. The bracket1502 can be locked in a selected rotational position by tightening thelock screw 1510A.

While the bracket 1502 can be rotated about the guide member 1204 andthe trajectory axis TCA, the axial position of the bracket 1502 alongthe trajectory axis TCA is fixed. The engagement between the projections1514A, 1514B and the grooves 1204A, 1204B prevents the bracket 1502 frommoving up or down (i.e., axially along) the guide member 1204. In thismanner, a desired distance between the lens 1558 and the patient accessaperture 1112 can be reliably maintained.

The position of the bracket 1502 on the guide member 1204 can also bereversed so that the bracket 1502 extends from the opposite side of theyoke 1120. More particularly, the clamp arms 1512 can be mounted on theguide member 1204 such that the projections 1514A and 1514B slidablyseat in the grooves 1204B and 1204A, respectively. FIG. 34 illustratesvarious positions of the bracket 1502 on either side of the frame 1100and across an exemplary range of rotational positions on each side.

In some applications, the bracket 1502 may be mounted on the guidemember 1204 as described above without tightening the screw 1510A. Inthis case, the bracket 1502 may be free to rotate about the guide member1204 if the bracket 1502 is struck by the yoke 1120, thereby preventingbinding or interference with the operation of the yoke 1120.

Other types of light transmission scopes 1552 and associated devices maybe employed in accordance with embodiments of the present invention. Insome embodiments, the light transmission scope 1552 is a lasertransmission scope operatively connected to a laser generator to directa laser beam at the patient through the patient access opening 1112. Insome embodiments, the light transmission scope 1552 is operativelyconnected to a light source without provision of a camera device.

According to some embodiments, the bracket 1502 is configured such that,when a fiber scope 1552 of prescribed dimensions is inserted in the bore1516, the outer jacket 1556 bottoms out in the bore 1516A and the lens1558 projects a prescribed distance below the bracket 1502. In thismanner, the lens 1558 is disposed at a prescribed distance from andangle with respect to the access opening 1112 and the burr hole.

Referring to FIG. 36, according to some embodiments, the bracket 1502can be readily snapped on and off of the guide member 1204. The bracket1502 may be formed of a resilient semi-rigid material permittingsufficient deflection of the clamp arms 1512 to release the projections1514A, 1514B from the grooves 1204A, 1204B when desired.

With reference to FIGS. 33 and 38-40, the targeting cannula 1200 of theframe 1100 corresponds to the targeting cannula 200 of the frame 100except as follows. The frame 1100 and targeting cannula 1200 can be usedin the same manner as the frame 100 and the targeting cannula 200 andare further modified or configured to facilitate insertion of aninterventional device 1217 (e.g., a probe, sheath, stylet, or the like;shown in dashed lines in FIG. 40) into and through the targeting cannula1200. The targeting cannula 1200 can be slid up and down in the passage1204C of the guide member 1204 as discussed above with regard to thetargeting cannula 200 and the guide member 204 to place (and, in someembodiments, secure) the targeting cannula 1200 in a raised or retractedposition as shown in FIG. 38 and in a lowered or extended position asshown in FIG. 40.

Referring to FIG. 38, the targeting cannula 1200 has a guide lumen tube1258. The targeting cannula 1200 has an inlet 1252 and an outlet 1254 onthe trajectory axis TCA and communicating with the guide bore 1250 ofthe guide lumen tube 1258 on the upper and lower ends thereof. Anannular tapered wall 1256 extends inwardly from the inlet 1252 to aninner opening 1257.

A guide member support cap 1261 is mounted on the upper end of thetubular guide member 1204. The cap 1261 has a through bore 1260 (FIG.40) and an inlet 1262 (FIG. 40) communicating with the bore 1260. Anannular wall 1264 (FIGS. 39 and 40) tapers from the inlet 1262 to anarrowed (as compared to the inlet 1262) passage 1266.

As shown in FIG. 39, according to some embodiments, the inlet 1252 ofthe targeting cannula 1200 has a diameter D1 (FIG. 39) that is at least20% greater than the diameter D2 of the inner opening 1257 and the guidebore 1250. According to some embodiments, the taper angle of the taperedwall 1256 with respect to the trajectory axis TCA is in the range offrom about 20 to 70 degrees. According to some embodiments, the depthfrom the inlet 1252 to the inner opening 1257 is in the range of fromabout 0.01 to 0.1 inch.

According to some embodiments, the inlet 1262 of the support cap 1261has a diameter D4 that is at least 5% greater than the diameter D5 (FIG.39) of the passage 1266 (FIG. 40). According to some embodiments, thetaper angle of the tapered wall 1264 (FIG. 40) with respect to thetrajectory axis TCA is in the range of from about 20 to 70 degrees.

The enlarged, tapered inlet 1252 aids the operator (e.g., physician) ininserting the elongate interventional device 1217 into the targetingcannula 1200. The tapered wall 1258 can also aid the operator in fullyfeeding the interventional device 1217 through the guide bore 1250. Thisassistance may be particularly advantageous when the interventionaldevice 1217 is to be inserted into the targeting cannula 1200 while thetargeting cannula 1200 is in its extended position (FIG. 40) and/or thepatient is in the bore of a magnet limiting a clinician's access to thecannula. Insertion of the interventional device 1217 may be furtherfacilitated by the enlarged, tapered inlet 1262 of the support cap 1261.

With reference to FIG. 41, the frame 1100 is shown therein with analternative targeting cannula 1200′ mounted in the guide member 1204 inplace of the targeting cannula 1200 according to further embodiments ofthe present invention.

The targeting cannula 1200′ can be configured in the same manner as thetargeting cannula 1200 but further includes a tubular extension 1259′having a reduced outer diameter D6 as compared to the inner diameter ofthe guide member passage 1204C. The reduced outer diameter of theextension 1259′ permits the extension 1259′ to be received into orthrough the passage 1266 of the support cap 1261 when the targetingcannula 1200′ is in the retracted position as shown in FIG. 41.

According to some embodiments, when the targeting cannula 1200′ is inthe retracted position, the tapered wall 1256′ begins below the taperedwall 1264 of the cap 1261 and extends up to a position adjacent oroverlapping with the cap 1261 to provide a continuous tapered wall fromthe opening 1262 to the inner opening 1257′. According to someembodiments, the top of the extension 1259′ is substantially flush withthe top of the narrowed passage 1266 of the cap 1261 when the targetingcannula 1200′ is in the retracted position.

The extension 1259′ provides additional length to the targeting cannula1200′ so that, when the targeting cannula 1200′ is in its extendedposition, the distance between the inlet 1252′ and the inlet 1262 isreduced, thereby making it easier for the operator to insert theinterventional device 1217 through the guide bore 1250′. By configuringthe extension 1259′ to be flush with but not extend above the upper endof the passage 1266 of the cap 1261, interference between the extension1259′ and other components mounted on the cap 1261 (e.g., the depth stop220) can be prevented.

With reference to FIGS. 33 and 42-44, the frame 1100 can include amounting system 1101 configured to allow assembly of the yoke 1120 ontothe base 1110 by an operator or the like when desired. According to someembodiments, the mounting system 1101 also permits the yoke 1120 to bedismounted from the base 1110 when desired. As discussed in more detailbelow, the mounting system 1101 can be configured to prevent or reducethe risk of installing the yoke 1120 on the base 1110 with anorientation other than a prescribed orientation.

A first part of the mounting system 1101 may be integrated into the base1110. The base 1110 includes a hub 1111 defining the patient accessopening 1112 and which can be secured to the patient by screws insertedthrough the screw holes 1114. A pair of struts 1115 extend from the hub1111 to support first and second arcuate rails or arms 1116A and 1116B.A first mount tab or extension 1160 depends from the first arm 1116A anda second mount tab or extension 1162 depends from the second arm 1116B.A generally vertical first mount slot 1161 is provided in the firstextension 1160 (accessible via the outer wall). The first mount slot1161 has a slot inlet 1161A on its upper end and a pivot hole 1161B onits lower end. A generally vertical second mount slot 1163 is providedin the second extension 1162. The second mount slot 1163 has a slotinlet 1163A on its upper end and a pivot hole 1163B on its lower end.

The yoke 1120 has first and second depending mount wings, tabs or arms1164 and 1165. As shown in FIG. 44, a mount hole 1164A is formed in themount arm 1164 and has internal threads 1164B (FIG. 44). A mount hole1165A is formed in the mount arm 1165 and has internal threads 1165B(FIG. 44).

As shown in FIGS. 42 and 44, the mounting system 1101 further includesfirst and second pivot screws 1166 and 1167 each including a respectiveknob 1166A, 1167A, an externally threaded shank 1166B, 1167B, and asmooth pivot pin or post 1166C, 1167C. The first pivot screw 1166 isscrewed into the first mount hole 1164A such that the pivot post 1166Cprojects inwardly beyond the hole 1164A. The second pivot screw 1167 isscrewed into the second mount hole 1165A such that the pivot post 1167Cprojects inwardly beyond the hole 1165A.

Referring to FIG. 42, to assemble the frame 1100, the yoke 1120 can bemounted on the base 1110 as follows. According to some embodiments, theyoke 1120 is mounted on the base 1110 before the base 1110 is mounted onthe patient and, according to some embodiments, after the frame 1100components are shipped from the manufacturer to the end user. Accordingto some embodiments, the platform 1130, the targeting cannula 1200, andthe guide member 1204 are preassembled by the manufacturer onto the yoke1120.

With the pivot screws 1166, 1167 installed in the holes 1164A, 1165A andthe opposed posts 1166C, 1167C projecting inwardly toward one another,the posts 1166C and 1167C are positioned above the slots 1161, 1163 andaligned with the slot inlets 1161A and 1163A, respectively. The yoke1120 is lowered onto the arcuate arms 1116 of the base 1110 such thatthe posts 1166C and 1167C slide into the slots 1161 and 1163,respectively, through the slot inlets 1161A and 1163A. The assemblercontinues to lower the yoke 1120 so that the posts 1166C, 1167C slidedown the slots 1161, 1163 until the posts 1166C and 1167C align with thepivot holes 1161B and 1163B, respectively, whereupon the posts 1166C and1167C seat within the pivot holes 1161B and 1163B. The yoke 1120 isthereby mounted on the base 1110 to pivot about the roll axis RA (i.e.,about the pivot posts 1166C, 1167C) as discussed above with regard tothe frame 100, the yoke 120 and the base 110.

According to some embodiments, the spacing between the slots 1161, 1163is greater than the spacing between the posts 1166C, 1167C and the mountextensions 1160, 1162 are resilient so that the extensions 1160, 1162are deflected outwardly until the posts align with the pivot holes1161B, 1163B, whereupon the spring bias of the mount extensions 1160,1162 forces the posts 1166C, 1167C to seat or snap fit into therespective pivot holes 1161B, 1163B. In this manner, unintendeddisengagement between the posts 1166C, 1167C and the pivot holes 1161B,1163B can be prevented or inhibited by the persistent spring biasresisting removal of the posts 1164C, 1165C from the pivot holes 1161B,1163B. The amount of spring loading between the posts 1166C, 1167C andthe mount extensions 1160, 1162 can be adjusted by screwing the pivotscrews 1166, 1167 into or out of the mount holes 1164A, 1165A.

According to some embodiments, the bottom walls of the opposed slots1161, 1163 taper outwardly with respect to one another in the directionfrom the slot inlets 1161A, 1163A to the pivot holes 1161B, 1163B. Withthis configuration, it may be easier for the assembler to initiateinsertion of the posts 1166C, 1167C into the slots 1161, 1163 withgreater resistance being presented as the posts 1166C, 1167C travel downthe slots 1161, 1163 and outwardly deflect the mount arms 1164, 1165.According to some embodiments, the slots 1161, 1163 taper outwardly atan angle of between about 1 and 15 degrees with respect to one another.

If desired, the yoke 1120 can be dismounted from the base 1110 bypulling the mount arms 1164, 1165 apart to release the posts 1166C,1167C from the pivot holes 1161B, 1163B and sliding the posts 1166C,1167C back up and out of the slots 1161, 1163. The pivot screws 1166,1167 can be screwed outwardly so that it is not necessary to spread thearms 1164, 1165 to release the posts 1166C, 1167C. If desired, thescrews 1166, 1167 can be fully removed from the yoke 1120. The knobs1166A, 1167A can be grasped and pulled by the operator to pull the arms1164, 1165 apart.

According to some embodiments, the first and second posts 1166C, 1167Chave different diameters D7 (FIG. 43) and D8 (FIG. 42) from one another,the first and second slots 1161, 1163 have different widths W1 (FIG. 42)and W2 (FIG. 43) from one another, and the first and second pivot holes1161B and 1163B have different diameters W1′ and W2′ (FIG. 44) from oneanother. More particularly, the diameter D7 is greater than the width W2and the diameter W2′ and somewhat less than the width W1 and thediameter W1′. The diameter D8 is somewhat less than the width W2 and thediameter W2′. As a result, the first post 1166C can only be insertedinto the first slot 1161, thereby preventing the assembler from mountingthe yoke 1120 on the base 1110 with the wrong relative orientationbetween the base 1110 and the yoke 1120.

With reference to FIGS. 33, 38, 45 and 46, the frame 1100 may furtherinclude a stabilizer system 1171 (FIG. 45) to control relative movementbetween the moving plate 1134 and a support table 1132 thereof(corresponding to the moving plate 134 and the support table 132,respectively, of the frame 100). The stabilizer system 1171 can therebycontrol relative movement between the targeting cannula 1200 and theplatform 1130.

The support table 1132 has sideward opening slots 1132A through whichends of the moving plate 1134 slide when the moving plate 1134 istranslated in the X-direction or the Y-direction with respect to thesupport table 1132. The stabilizer system 1171 includes a pair ofopposed stabilizer mechanisms 1170 mounted in respective ones of theslots 1132A. The stabilizer mechanisms 1170 can be configured and usedin the same manner and only one of the stabilizer mechanisms 1170 willbe described in detail hereinafter, it being appreciated that thisdescription likewise applies to the other stabilizer mechanism 1170.

Referring to FIGS. 45 and 46, the stabilizer mechanism 1170 includes apressure member or bearing or rub bar 1172 and set screws 1174. The rubbar 1172 is mounted in the slot 1132A between the top of the movingplate 1134 and an overlying crossbar 1132B of the support table 1132.The set screws 1174 are threadedly mounted in the threaded bores 1176 inthe crossbar 1132B and extend into a groove 1172B in the rub bar 1172 toretain the rub bar 1172 in the slot 1132A. The rub bar 1172 may includeindicia 1172C corresponding to the indicia 138 of the frame 100 andcooperating with a scale 1136 on the moving plate 1134.

The screws 1174 and bores 1176 can serve as an adjustment mechanism byrotating the screws 1174 in or out with respect to the crossbar 1132C toselectively adjust the height H of the slot 1132A. In this manner, theslack or gap between the moving plate 1134 and the support table 1132 inthe slot 1132A can be reduced or effectively eliminated.

According to some embodiments, the screws 1174 and the threaded bores1176 serve as a loading mechanism to apply a load to the rub bar 1172.More particularly, the operator or assembler can rotate the screws toforce the rub bar 1172 to compressively load the moving plate 1134 viaan engagement surface 1172A of the rub bar 1172. The rub bar 1172 maypresent a frictional resistance to sliding motion of the moving plate1134.

According to some embodiments, the operator or assembler sets thecompressive load on the moving plate 1134 using the stabilizermechanisms 1170 at a level that permits the moving plate 1134 to slidein the slots 1132A without binding but which does not permit significantmovement between the moving plate 1134 and the support table 1132 otherthan in the X and Y directions. According to further embodiments, thescrews 1174 are adjusted so that the rub bar 1172 does not compressivelyload the moving plate 1172.

The stabilizer system 1171 can be used to prevent or reduce tilting ofthe moving plate 1134, and thus the targeting cannula 1200, relative tothe support table 1132 and the base 1110. The stabilizer system 1171 cancorrect for oversized tolerances between the moving plate 1134 and thesupport table 1132 (e.g., from manufacturing and/or usage of the frame1100).

With reference to FIGS. 38, 47 and 48, the frame 1100 can include a locksystem 1179 to temporarily prevent or resist movement of the upper(i.e., Y-direction movement) moving plate 1134 and/or the lower (i.e.,X-direction movement) moving plate 1135 (FIG. 46) with respect to thesupport table 1132. Such movement control may be desirable to preventdamage to the frame 1110 during shipping and/or to prevent unintendedX-Y displacement of the targeting cannula 1200 when setting thetargeting trajectory, for example.

With reference to FIG. 38, the lock system 1179 includes a lock clip1178, a through hole 1134L (in the upper moving plate 1134), a throughhole 1135L (in the lower moving plate 1135), and a hole 1132L (in thesupport table). As shown in FIG. 48, the lock clip 1178 may be generallyU-shaped and integral with a lock leg 1178A, a clip leg 1178B, a bend1178C, and a latch feature 1178D. The lock clip 1178 may be formed ofany suitable MRI-compatible material, such as a substantially rigidpolymeric material.

In use, the lock leg 1178A of the lock clip 1178 is inserted through theholes 1134L, 1135L, 1132L and the latch feature 1178D is securedunderneath a protruding end portion of the upper moving plate 1134 (seeFIGS. 38 and 47). According to some embodiments, the lock clip 1178 isinstalled at the assembly factory. The lock clip 1178 may be retained inthe locking position until after the frame 1110 is mounted on thepatient's head, for example. The lock clip 1178 can be removed from theplatform 1130 by pulling the latch feature 1178D free of the end of themoving plate 1134 and withdrawing the lock leg 1178A from the holes1134L, 1135L, 1132L.

With reference to FIG. 49A, according to some embodiments, fiducialmarkers are relatively configured on the frame 1100, and in someembodiments on the base 1110, in a manner that facilitates or enablespositive determination of an orientation of the frame 1100 from an MRimage. According to some embodiments, the spacing between adjacentfiducial markers on the frame 1100 (e.g., on the base 1110) isnon-uniform. According to some embodiments, the fiducial markers aremounted on the frame 1100 in a rotationally asymmetric layout. Forexample, according to some embodiments, the fiducial markers 1182, 1184,1186 are mounted on the base 1110 in a rotationally asymmetric layout orconfiguration. By reference to this prescribed asymmetry, an affirmativeorientation of the base 1110 (and, thus, the frame 1100 and thetrajectory guide axis TCA) in free space can be determined from MRIimage data of an MR image of the frame 1100.

According to some embodiments, the rotationally asymmetric layoutincludes locating the fiducial markers such that a first fiducial marker(e.g., the fiducial marker 1184) is closer to an adjacent secondfiducial marker (e.g., the fiducial marker 1186) than it is to a thirdadjacent fiducial marker (e.g., the fiducial marker 1182). According tosome embodiments, the rotationally asymmetric layout includes locatingthe fiducial markers 1182, 1184, 1186 such that two of the fiducialmarkers 1182, 1184, 1186 are closer to one another than either is to thethird. According to some embodiments and as illustrated, the fiducialmarkers 1182, 1184, 1186 are positioned on the base 1110 such that theircenter points (i.e., the center points of their center openings 1187C)are each located on a circle C. The fiducial markers 1184 and 1186 arecircumferentially spaced apart from one another on the circle C ashorter distance than either fiducial marker 1184, 1186 iscircumferentially spaced apart from the fiducial marker 1182 (i.e., thearc lengths of the circle segments between the fiducial markers 1184,1186 and the fiducial marker 1182 are greater than the arc length of thecircle segment between the fiducial markers 1184, 1186).

In some embodiments, the center point CP of the circle C issubstantially coincident with the center point of the patient accessopening 1112. According to some embodiments, the center point CP lies onthe guide axis TCA (FIG. 38) when the targeting cannula 1200 ispositioned in a top dead center position with respect to the base 1110and the frame 1100 is in a home position as shown in FIGS. 33, 34, 38and 47. According to some embodiments, when the frame 1100 is in thehome position, the trajectory guide axis TCA is substantially orthogonalwith the plane of the patient access opening 1112 or the burr hole.According to some embodiments, when the lock clip 1178 is in the lockingposition (FIGS. 38 and 47) the trajectory guide axis TCA intersects thecenter point CP irrespective of the pitch or roll setting of the frame1100 (e.g., the center point CP may be coincident with the remote centerof motion (RCM)).

According to some embodiments, the fiducial markers 1182, 1184, 1186 andthe circle C all lie on a common fiducial marker plane F-F (FIGS. 38 and44). According to some embodiments, the fiducial marker plane F-F isspaced apart above (and in some embodiments, parallel to) the plane ofthe patient access opening 1112 and the burr hole (when mounted on thepatient).

According to some embodiments, the frame 1100 is secured to thepatient's head and the patient is placed within the MRI scanner 75. TheMRI scanner scans the patient and the frame 1100 and generatescorresponding MR image data. From the MR image data, MR images areobtained of the patient's head that visualize the patient's skull andbrain. Certain known anatomical landmarks can be included in the MRimages. The MR images also visualize the MRI-visible fiducial markers1182, 1184, 1186, which serve as MRI-visible landmarks associated withthe frame 1100. The MR images can include volumetric high-resolutionimages of the brain.

With reference to FIG. 49B, the location and orientation of the frame1100 on the head is identified in the MR images. Certain knownanatomical landmarks can be used. For example, reference may be made tophysiological landmarks such as the AC, PC and MCP points (brain atlasesgive the location of different anatomies in the brain with respect tothese points) and other anatomical landmarks of the patient's head.

The location and orientation of the frame 1100 may be determined byvisually displaying the fiducial markers 1182, 1184, 1186 orrepresentations thereof in an image 40 on the display 500 where they canbe readily identified by the operator (for example, as shown in FIG.49B). The image 40 may further include the MR image of the patient 11.The operator can determine the orientation of the base 1110 on thepatient's head and in free space by determining the relative positionsof the fiducial markers 1182, 1184, 1186.

Alternatively or additionally, an electronic controller 302 mayprogrammatically identify or recognize and analyze and/or report and/orvisualize the fiducial markers 1182, 1184, 1186 in the image data.

According to some embodiments, the controller 302 processes the acquiredimage data to programmatically recognize, orient and place the base 1110in the logical space (i.e., MR volume) frame of reference. According tosome embodiments, the controller 302 uses an algorithm toprogrammatically determine the position of the base 1110 in the logicalspace. According to some embodiments, the controller 302 uses apre-stored reference image or images to programmatically determine theposition of the base 1110 in the logical space.

Once the controller 302 has assessed the position (e.g., includingorientation) of the base 1110 in the logical space, the controller 302can use this data to assess or track the frame 1100 or enable or assistidentification of the frame orientation by the operator. For example,the controller 302 may enhance (e.g., add increased image contrast) orinsert highlighted representations of the fiducial markers 1182, 1184,1186 into the image 40 as provided on the display 500 in order to makethe fiducial markers 1182, 1184, 1186 visually stand out in the image40. The controller 302 can provide various additional functionality onceit has recognized the fiducial markers 1182, 1184, 1186 in the MR image.Further methods and operations of the controller are disclosed in U.S.patent application Ser. No. 12/236,854, filed Sep. 24, 2008, now U.S.Patent No. 8,315,689, issued Nov. 20, 2012, the disclosure of which isincorporated herein by reference.

According to some embodiments, the controller 302 generates, fits andoverlays or superimposes a graphical grid overlay 45 onto the MR image40 as shown in FIG. 49B, for example, to delineate the location anddistribution of the fiducial markers 1182, 1184, 1186, the base 1110and/or the access opening 1111 on the head 11. The positions andorientations of fiducial markers 1182, 1184, 1186 or the base 1110 maybe correlated to the image of the head 11 by the graphical grid overlay45. According to some embodiments, the controller 302 processes the MRimage without displaying the fiducial markers 1182, 1184, 1186 and/orthe grid overlay 45 to the operator.

With reference to FIGS. 44, 49A and 50, the frame 1100 may be providedwith features to reliably and accurately locate the fiducial markers1182, 1184, 1186 on and with respect to the base 1110. The fiducialmarkers 1182, 1184, 1186 are each toroidal in shape and have a centralopening 1187C. As shown in FIGS. 42, 43 and 49A, the base 1110 caninclude cavities 1110A′, 1110B′, and 1110C′, defined in part byplatforms 1110A, 1110B, 1110C, configured to receive the fiducialmarkers 1182, 1184, and 1186, respectively. The base 1110 furtherincludes a central locator projection 1111 in each cavity 1110A, 1110B,1110C extending up from the platform 1110A′, 1110B′, and 1110C′ thereof.When the fiducial markers 1182, 1184, 1186 are mounted in the cavities1110A, 1110B, 1110C, each location projection 1111 is received in therespective central opening 1187C to positively locate the fiducialmarker 1182, 1184, 1186 in the cavity 1110A, 1110B, 1110C. According tosome embodiments, each locator projection 1111 is located on the circleC (FIG. 49A).

According to some embodiments, the outer diameter of each locatorprojection 1111 is substantially the same as the inner diameter of thereceiving central opening 1187C.

With reference to FIG. 51, each fiducial marker 1182, 1184, 1186 mayinclude a torus body 1187A (surrounding the central opening 1187C) and afill nipple or tab 1187B extending radially from the body 1187A. Thefill tab 1187B may be a manufacturing artifact from a tube used to fillthe body 1187A with an MRI-visible material such as an MRI-visibleliquid, for example. Suitable fiducial markers may include donut-shapedmarkers available from Beekley Corporation.

The seat cavity 1110A substantially fully (i.e., 360 degrees)circumferentially surrounds the fiducial marker 1182 when the fiducialmarker 1182 is installed on the base 1110. However, in order toaccommodate the tab 1187B of the fiducial marker 1182, a relief orcutout 1110D is formed in the base 1110 at or contiguous with the cavity1110A. The tab 1187B of the fiducial marker 1182 extends through thecutout 1110D.

The order steps may be different from that described herein and not allsteps may be used or some of the steps may be used with other steps. Insome embodiments, the frame 1100 can be mounted and assembled in adifferent order than that set forth above. According to someembodiments, the frame 1100 is mounted on the patient and assembled asfollows. The burr hole is formed. The base 1100 is then mounted on thehead about the burr hole. A burr hole ring is then mounted on the burrhole through the access opening 1112. According to some embodiments, theaccess opening 1112 is sized and shaped to prevent contact between theburr hole ring and the base 1110 when both are mounted on the patient'shead. The yoke 1120 is then mounted on the base 1110 (e.g., in themanner described above). According to some embodiments, the yoke 1120 isremoved from the base 1110 after the interventional procedure isexecuted using the frame 1100 in order to facilitate access to thescrews securing the base 1110 to the head. The screws can then beremoved to dismount the base 1110 from the head.

According to some embodiments, the lock clip 1178 is retained in thelocking position (FIGS. 38 and 47) at least until the yoke 1120 ismounted on the base 1110. According to some embodiments, the lock clip1178 is retained in the locking position at least until the pitch androll adjustments have been made to place the targeting cannula 1200 inthe desired orientation. The lock clip 1178 may thereafter be removed inorder to make an X-Y adjustment or adjustments to the targeting cannula1200.

As discussed above with reference to FIG. 10A, the remote control unit400 may include locking mechanisms 401 a, 404 b, 404 c to secure thesettings of the frame 1100. Additionally or alternatively, the frame1100 may be constructed and configured to effectively self-lock thepositions of the frame 1100 (i.e., the settings of the yoke 1120, thesupport table 1132, the X-direction moving plate 1134 and theY-direction moving plate 1135) up to at least a prescribed load, inwhich case the locking mechanisms 404 a, 404 b, 404 c may be omitted orremain unused. More particularly, according to some embodiments, thetolerances between the relatively movable components of the frame 1100and/or the resistance of the onboard adjustment mechanisms (e.g., thegear drives) are selected such that at least a relatively highprescribed threshold force or torque must be applied to each respectiveactuator 1140 a, 1140 b, 1140 c, 1140 d (FIG. 33) in order to change thecorresponding roll, pitch, X or Y adjustment (i.e., to change therelative position of the corresponding component). With respect to the Xand Y adjustments, this may be accomplished by adjusting the stabilizersystems 1171 so that the rub bars 1172 sufficiently bear upon the movingplate 1134. The drive shafts or control cables 150 a-d can be permittedto float freely.

In some embodiments, the frames 100, 1100 are sized and shaped so thatthey may be simultaneously mounted side-by-side on a patient's head toconduct a bilateral surgical procedure as described herein withoutcontacting or interfering with one another as illustrated in FIG. 52.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. The invention is defined by the following claims, withequivalents of the claims to be included therein.

That which is claimed is:
 1. An MRI-guided interventional system for usewith a body of patient and an interventional device, the systemincluding: a trajectory guide frame for guiding the interventionaldevice with respect to a body of a patient in an MRI-guided procedure,the trajectory guide frame including: a base having a patient accessaperture therein, wherein the base is configured to be secured to thebody of the patient; a platform mounted on the base and including asupport table and a moving plate that is translatable relative to thesupport table and the base along a translational axis; a targetingcannula mounted on the moving plate for movement therewith relative tothe support table and the base, the targeting cannula including anelongate guide bore therethrough, the guide bore defining a trajectoryaxis and being configured to guide placement of the interventionaldevice in vivo; and a stabilizer mechanism operable to selectivelycontrol movement between the support table and the moving plate tostabilize a position of the targeting cannula with respect to the base;wherein the trajectory guide frame is operable to translate the movingplate and thereby the targeting cannula along the translational axisrelative to the base to position the trajectory axis to a desiredintrabody trajectory to guide placement of the interventional device invivo; and wherein the translational axis is transverse to the trajectoryaxis.
 2. The system of claim 1 including an elongate interventionaldevice configured to be serially inserted along the trajectory axisthrough the guide bore and into the body of the patient in vivo.
 3. Thesystem of claim 1 wherein: the translational axis is an X-translationalaxis; the moving plate is translatable relative to the support table andthe base along a Y-translational axis transverse to the X-translationalaxis; and the Y-translational axis is transverse to the trajectory axis.4. The system of claim 1 further including a yoke movably mounted on thebase and rotatable relative to the base about a pivot axis, wherein theplatform is mounted on the yoke for rotation therewith and the platformis configured to permit translational movement of the moving plate withrespect to the yoke.
 5. The system of claim 1 wherein: the stabilizermechanism includes an adjustment device and a rub bar; and the rub barand the support table cooperatively define a slot through which themoving plate slides in contact with the rub bar.
 6. The system of claim5 wherein the adjustment device includes a loading device operable toapply a load to the rub bar to compressively load the moving plate inthe slot between the support table and the rub bar.
 7. The system ofclaim 5 wherein the loading device includes at least one screw.
 8. Atrajectory guide frame for guiding an interventional device with respectto a body of a patient in an MRI-guided procedure, the trajectory guideframe comprising: a base having a patient access aperture therein,wherein the base is configured to be secured to the body of the patient;a platform mounted on the base and including a support table and amoving plate that is movable relative to the support table and the base;a targeting cannula mounted on the moving plate for movement therewithrelative to the support table and the base, the targeting cannulaincluding a guide bore therethrough that is configured to guideplacement of the interventional device in vivo; and a stabilizermechanism operable to selectively control movement between the supporttable and the moving plate to stabilize a position of the targetingcannula with respect to the base; wherein: the stabilizer mechanismincludes an adjustment device and a rub bar; and the rub bar and thesupport table cooperatively define a slot through which the moving plateslides in contact with the rub bar.
 9. The trajectory guide frame ofclaim 8 wherein the adjustment device is operable to apply a load to therub bar to compressively load the moving plate in the slot between thesupport table and the rub bar.
 10. The trajectory guide frame of claim 8wherein the loading device includes at least one screw.
 11. A method ofadjusting a trajectory of an in vivo interventional device, comprising:affixing a trajectory guide frame to a body of a patient in anMRI-guided procedure, the trajectory guide frame including: a basehaving a patient access aperture therein, wherein the base is configuredto be secured to the body of the patient; a platform mounted on the baseand including a support table and a moving plate that is translatablerelative to the support table and the base along a translational axis; atargeting cannula mounted on the moving plate for movement therewithrelative to the support table and the base, the targeting cannulaincluding an elongate guide bore therethrough, the guide bore defining atrajectory axis and being configured to guide placement of theinterventional device in vivo; and a stabilizer mechanism operable toselectively control movement between the support table and the movingplate to stabilize a position of the targeting cannula with respect tothe base; wherein the trajectory guide frame is operable to translatethe moving plate and thereby the targeting cannula along thetranslational axis relative to the base; and wherein the translationalaxis is transverse to the trajectory axis; and while the patient remainsin position in a magnetic field associated with an MRI scanner,adjusting the trajectory guide frame to translate the moving plate andthereby the targeting cannula along the translational axis relative tothe base to position the trajectory axis to a desired intrabodytrajectory to guide placement of the interventional device in vivo. 12.The method of claim 11 wherein: the stabilizer mechanism includes anadjustment device and a rub bar; the rub bar and the support tablecooperatively define a slot through which the moving plate slides incontact with the rub bar; the adjustment device includes a loadingdevice operable to apply a load to the rub bar to compressively load themoving plate in the slot between the support table and the rub bar; andthe method includes selectively operating the loading device to changethe compressive load on the moving plate.
 13. An MRI-guidedinterventional system, comprising: a trajectory guide frame with acooperating targeting cannula, wherein the trajectory guide frame isconfigured to translate and rotate such that the targeting cannula canbe positioned to a desired intrabody trajectory, and wherein thetargeting cannula includes a guide bore therethrough that is configuredto guide placement of an interventional device in vivo, wherein thetrajectory guide frame comprises: a base having a patient accessaperture formed therein, wherein the base is configured to be secured tothe body of a patient; a yoke movably mounted to the base and rotatableabout a roll axis; a platform movably mounted to the yoke and rotatableabout a pitch axis, wherein the platform comprises an X-Y support tableand a moving plate, wherein the moving plate is movably mounted to thesupport table to move in an X-direction and Y-direction relative to thebase; and a stabilizer mechanism operable to selectively controlmovement between the X-Y support table and the moving plate to stabilizea position of the targeting cannula with respect to the base.
 14. Thesystem of claim 13 including at least one user-activatable actuatoroperably connected to the trajectory guide frame and configured totranslate and rotate the trajectory guide frame relative to the body ofthe patient so as to position the targeting cannula to a desiredintrabody trajectory.